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    <title>A-Level Math Revision — Pete&#x27;s Blog</title>
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    <description>Weekly Edexcel A-Level &amp; IAL Maths posts — exam strategy, worked examples and study routines from a serving teacher and examiner. Pete Bromfield.</description>
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      <title>A-Level Math Revision — Pete&#x27;s Blog</title>
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      <title>How to write mathematical working that scores marks (not just correct answers)</title>
      <link>https://alevelmathrevision.com/blog-alevel/method-marks-writing.html</link>
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      <pubDate>Sat, 11 Apr 2026 09:00:00 +0000</pubDate>
      <description>The four sentences that turn a right answer into a full-marks solution. Real examiner examples inside.</description>
      <category>Method marks</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/method-marks-writing.jpg" alt="How to write mathematical working that scores marks (not just correct answers)" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>"I got the right answer but only got 3 out of 5." Every A-Level teacher has heard this a thousand times. Here's why — and how to fix it in your next mock.</p>
<p>Edexcel marks are split into three types:</p>
<ul>
<li><strong>M marks</strong> (Method): awarded for choosing and executing a valid approach.</li>
<li><strong>A marks</strong> (Accuracy): awarded for correct numerical or algebraic outcomes at each step.</li>
<li><strong>B marks</strong> (Independent): awarded for stating a known fact or applying a specific technique correctly.</li>
</ul>
<p>You earn M and B marks by WRITING what you're doing, not just doing it. Here's the four-sentence template.</p>
<h2>The four sentences</h2>
<p><strong>Sentence 1 — What am I about to do?</strong></p>
<p>"To find the stationary points, differentiate $y$ with respect to $x$ and set the derivative to zero."</p>
<p>This earns the method mark BEFORE you've done a single calculation. It states the technique.</p>
<p><strong>Sentence 2 — Execute the technique, showing the intermediate line.</strong></p>
<p>"$\dfrac{dy}{dx} = 6x^2 - 12x$"</p>
<p>Not just "$dy/dx = 0$"; write the actual derivative expression.</p>
<p><strong>Sentence 3 — Solve, showing at least one factorisation or substitution step.</strong></p>
<p>"$6x(x - 2) = 0$ so $x = 0$ or $x = 2$."</p>
<p>Factorisation is a common examiner-favourite intermediate. Show it.</p>
<p><strong>Sentence 4 — State the answer clearly, with units if applicable.</strong></p>
<p>"The stationary points are at $x = 0$ and $x = 2$. Substituting back, the coordinates are $(0, 4)$ and $(2, -4)$."</p>
<p>Now you've earned every mark.</p>
<h2>The examiner's-eye view</h2>
<p>An examiner has a mark scheme with roughly this structure:</p>
<ul>
<li>M1: Attempts to differentiate ($6x^2 - 12x$, allow one slip)</li>
<li>A1: Correct derivative ($6x^2 - 12x$)</li>
<li>M1: Sets to zero (or equivalent)</li>
<li>A1: Finds $x$-values ($0$ and $2$)</li>
<li>A1: Correct $y$-values</li>
</ul>
<p><strong>Five marks.</strong> If you skip straight from the original equation to "$x = 0, x = 2$" — even if correct — you're at risk of losing the two M marks. Two out of five gone.</p>
<h2>The showing-off phrases</h2>
<p>These phrases signal to the examiner "I know what I'm doing" and often score the method mark:</p>
<ul>
<li>"By the chain rule…"</li>
<li>"Using the product rule with $u = \ldots, v = \ldots$…"</li>
<li>"Applying the identity $\sin^2\theta + \cos^2\theta \equiv 1$…"</li>
<li>"Substituting into the given equation…"</li>
<li>"By the quotient rule…"</li>
<li>"Since the discriminant is negative, there are no real roots…"</li>
</ul>
<p>Even if the subsequent algebra is wobbly, these phrases lock in the method mark.</p>
<h2>The show-that trap</h2>
<p>For a "show that" question — where the final answer is given — you MUST show every step. Skipping intermediate lines because "it's obvious" loses marks. If the question says "show that $x = 5$", the examiner wants:</p>
<ul>
<li>The starting equation.</li>
<li>Every rearrangement.</li>
<li>The final line that reads "$x = 5$".</li>
</ul>
<p>Missing any of these can cost the full 3 or 4 marks.</p>
<h2>The Q9 example</h2>
<p>Full-marks working for a typical Q9 involves:</p>
<ul>
<li>A labelled diagram (if geometric).</li>
<li>A named theorem or method ("by the cosine rule…").</li>
<li>The formula stated in full ($\cos A = \dfrac{b^2 + c^2 - a^2}{2bc}$).</li>
<li>The substitution line with numbers.</li>
<li>The arithmetic step.</li>
<li>A concluding sentence with the answer + units.</li>
</ul>
<p>Six lines. Every one of them earns something.</p>
<h2>Your drill</h2>
<p>Take any past-paper question you've already done. Mark it against the mark scheme with two colours:</p>
<ul>
<li>Green: marks you earned.</li>
<li>Red: marks the mark scheme awards that you didn't score.</li>
</ul>
<p>Look at every red mark. Nine times out of ten, it's a method mark you missed because you didn't state the technique.</p>
<p>Do this for five questions. Your mark-per-question average will lift by 15-25% in the next mock — same maths, better writing.</p>

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      <title>Edexcel A-Level vs IAL: which board should you actually sit?</title>
      <link>https://alevelmathrevision.com/blog-alevel/edexcel-uk-vs-ial.html</link>
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      <pubDate>Wed, 08 Apr 2026 09:00:00 +0000</pubDate>
      <description>Content, timing, calculator rules, university acceptance. The honest comparison for schools weighing both.</description>
      <category>Choosing</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/edexcel-uk-vs-ial.jpg" alt="Edexcel A-Level vs IAL: which board should you actually sit?" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>For international schools, this is the annual dilemma. UK 9MA0 or IAL? Both are Edexcel. Both are recognised by every UK university. But they are NOT interchangeable, and the choice has real consequences for teaching, timetabling and student outcomes.</p>
<p>Here's the honest side-by-side.</p>
<h2>Content coverage</h2>
<p><strong>UK 9MA0</strong>: A single linear qualification. Pure (2/3 of content) + Applied (1/3, half Statistics half Mechanics). Everything is examined at the end of Year 13 across three 2-hour papers.</p>
<p><strong>IAL</strong>: Modular. Papers P1, P2, P3, P4 for pure content, plus a Statistics module (S1) and a Mechanics module (M1). Each paper is a separate exam sitting. Papers P1 and S1 can be taken as early as end of Year 12.</p>
<p><strong>Verdict</strong>: If you value in-year assessment and multiple resit chances, IAL. If you want the syllabus to align with UK Year 13 finals and one big push, 9MA0.</p>
<h2>Difficulty and depth</h2>
<p><strong>UK 9MA0</strong>: Notably harder than IAL, particularly in Pure. The applied content is applied in a more integrated way — statistics and mechanics questions often require pure-maths manipulation as sub-steps.</p>
<p><strong>IAL</strong>: The individual modules are shorter and tightly scoped. P1 covers algebra + coordinate geometry + differentiation basics; P2 goes to trig + integration + logs. Content is packaged; there's less cross-linking.</p>
<p><strong>Verdict</strong>: IAL is more predictable per module. 9MA0 is broader and more integrative.</p>
<h2>Timing</h2>
<p><strong>UK 9MA0</strong>: Three 2-hour papers, all at end of Year 13. High-stakes single window.</p>
<p><strong>IAL</strong>: Each paper is 90 minutes. Papers can be spread over Year 12 January, Year 12 May/June, Year 13 January, Year 13 May/June — up to four sittings, with resits available.</p>
<p><strong>Verdict</strong>: IAL is kinder to students who don't perform well in the June session. 9MA0 concentrates all risk into one window.</p>
<h2>Calculator rules</h2>
<p><strong>UK 9MA0</strong>: Non-calculator paper is Paper 1 (~40% of the qualification). Calculator allowed on Papers 2 and 3.</p>
<p><strong>IAL</strong>: Calculator allowed on every paper. Non-calculator content is essentially absent.</p>
<p><strong>Verdict</strong>: If your students have shaky non-calculator algebra, IAL is significantly kinder. But 9MA0 forces the algebra to be sharp — a genuine long-term benefit.</p>
<h2>University acceptance</h2>
<p>Both are accepted by every UK university and by every US and Canadian university that accepts A-Levels. Oxford and Cambridge accept both. Medicine schools accept both.</p>
<p><strong>Small caveats</strong>: Some competitive courses (Maths, Engineering, Computer Science at top-25 UK unis) list "A-Level Maths" as the standard entry. They accept IAL, but the offer may specifically require A-Level Further Maths or an equivalent (STEP, MAT). If your students are targeting these, check the course pages individually.</p>
<p><strong>Verdict</strong>: For 99% of destinations, no difference. For competitive Maths / Engineering, verify per course.</p>
<h2>Teaching workload</h2>
<p><strong>UK 9MA0</strong>: One SoW to build, one set of past papers to prep, one exam window to teach toward. Simpler for a small maths department.</p>
<p><strong>IAL</strong>: Multiple SoWs to build, different exam windows to prep for, more admin. But each module is short enough that revision cycles are natural.</p>
<p><strong>Verdict</strong>: 9MA0 is easier to run. IAL is easier to sit.</p>
<h2>My take</h2>
<p>If your school is UK-based or your student cohort will predominantly apply to UK universities and you have strong non-calculator algebra teaching, <strong>9MA0</strong> is the qualification that will produce the strongest mathematicians.</p>
<p>If your school is international, your students want multiple exam sittings, and you value the predictability of modular assessment, <strong>IAL</strong> is the pragmatic choice.</p>
<p>Both are recognised. Both work. But they demand different teaching. The wrong choice for your context leads to disengaged students and stressed staff. Pick deliberately.</p>
<p>alevelmathrevision.com supports both boards — the topic engines, formula guides and Path to A* all filter by board, so a mixed department can use one platform for both cohorts.</p>

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      <title>The normal distribution: the two calculator moves that unlock every question</title>
      <link>https://alevelmathrevision.com/blog-alevel/normal-distribution-calculator-tricks.html</link>
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      <pubDate>Sat, 04 Apr 2026 09:00:00 +0000</pubDate>
      <description>Two Casio CG50 tricks, one page. Once you&#x27;ve seen these, S1 stats stops being scary.</description>
      <category>Statistics · S1</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/normal-distribution-calculator-tricks.jpg" alt="The normal distribution: the two calculator moves that unlock every question" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>Every S1 paper has 6-10 marks of normal distribution. Every one of those marks is accessible if you know two calculator moves cold. Here they are, on one page.</p>
<h2>Move 1 — Finding a probability</h2>
<p>Question shape: "$X \sim N(\mu, \sigma^2)$. Find $P(a < X < b)$."</p>
<p><strong>Casio CG50 keystrokes:</strong></p>
<ul>
<li>Menu → STAT</li>
<li>DIST → NORM → Ncd (normal cumulative distribution)</li>
<li>Lower: $a$</li>
<li>Upper: $b$</li>
<li>$\sigma$: standard deviation (NOT variance)</li>
<li>$\mu$: mean</li>
</ul>
<p>Press EXE. The probability is on-screen.</p>
<p><strong>Common trap</strong>: entering $\sigma^2$ instead of $\sigma$. The question gives you the variance; the calculator wants the standard deviation. Take the square root FIRST.</p>
<p><strong>For $P(X < a)$</strong>: set Lower to a very negative number (e.g. $-10^{99}$). The keystroke on Casio is (-)(EXP)99.</p>
<p><strong>For $P(X > a)$</strong>: set Upper to a very large number (e.g. $10^{99}$). Keystroke: EXP 99.</p>
<h2>Move 2 — Finding a value from a probability</h2>
<p>Question shape: "$X \sim N(\mu, \sigma^2)$. Find $a$ such that $P(X < a) = 0.85$."</p>
<p>This is the INVERSE normal — one of the least-known and highest-yielding calculator moves in the S1 syllabus.</p>
<p><strong>Casio CG50 keystrokes:</strong></p>
<ul>
<li>Menu → STAT</li>
<li>DIST → NORM → InvN (inverse normal)</li>
<li>Area: 0.85 (the given probability)</li>
<li>$\sigma$: standard deviation</li>
<li>$\mu$: mean</li>
<li>Tail: LEFT (for "$P(X < a)$"), RIGHT (for "$P(X > a)$"), or CNTR (for two-tailed).</li>
</ul>
<p>Press EXE. The value of $a$ is on-screen.</p>
<h2>The full workflow</h2>
<p>Every normal-distribution question fits one of these two moves. Read the question:</p>
<ul>
<li>Does it give you a value ($a$) and ask for a probability? → <strong>Move 1</strong> (Ncd).</li>
<li>Does it give you a probability and ask for a value ($a$)? → <strong>Move 2</strong> (InvN).</li>
<li>Does it give you a mean and standard deviation and ask both? Do them separately.</li>
</ul>
<h2>The three-mark example</h2>
<p>*"$X \sim N(50, 100)$. Find $P(X > 65)$."*</p>
<ul>
<li>$\sigma^2 = 100$ → $\sigma = 10$.</li>
<li>Ncd, Lower = 65, Upper = $10^{99}$, $\sigma = 10$, $\mu = 50$.</li>
<li>Answer: $P(X > 65) \approx 0.0668$.</li>
</ul>
<p>Total time: 30 seconds.</p>
<h2>The four-mark inverse example</h2>
<p>*"$X \sim N(80, \sigma^2)$. $P(X > 90) = 0.10$. Find $\sigma$."*</p>
<ul>
<li>This is inverse — we know the probability (0.10) and need to work backwards.</li>
<li>Standardise: $Z = \dfrac{90 - 80}{\sigma}$; $P(Z > z) = 0.10 \Rightarrow z \approx 1.2816$ (InvN, Area 0.9, Tail Left, $\sigma = 1$, $\mu = 0$).</li>
<li>So $\dfrac{10}{\sigma} = 1.2816 \Rightarrow \sigma \approx 7.80$.</li>
</ul>
<p>Yes — you use InvN on the STANDARD normal (mean 0, sd 1) first to find $z$, then solve for $\sigma$. This is the third-most-common exam pattern and it catches half the cohort every year.</p>
<h2>Setting up your calculator</h2>
<p>Two settings to check before the paper:</p>
<p>1. <strong>Angle</strong>: RADIAN (for calculus questions) or DEGREE (for stats questions with trig). Toggle via SETUP.</p>
<p>2. <strong>Fraction format</strong>: display fractions (d/c) or decimals (a b/c) — your choice, but stick to one throughout the paper for consistency.</p>
<h2>Your drill</h2>
<p>Print the two moves. Do six normal-distribution questions from past papers using ONLY these two moves. Time yourself — target: under 3 minutes per question. If you're going over, you're second-guessing the input. Trust the calculator.</p>
<p>Two moves, six questions, 45 minutes of drill. Ten marks unlocked forever.</p>

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      <title>The last 48 hours before an Edexcel Maths paper: what to actually do</title>
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      <pubDate>Wed, 01 Apr 2026 09:00:00 +0000</pubDate>
      <description>Not what your teacher says. Not what your friend says. What actually works — from someone who marks these papers.</description>
      <category>Exam skills</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/last-48-hours-before-exam.jpg" alt="The last 48 hours before an Edexcel Maths paper: what to actually do" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>The last 48 hours don't add knowledge. They stabilise the knowledge you already have. Get this window wrong and you can lose 15% of your ability to recall under pressure — regardless of how well you knew the material two weeks earlier.</p>
<p>Here's what actually works, sourced from what I see my top students do year after year.</p>
<h2>T-48 hours (Friday, if the exam is Monday)</h2>
<p><strong>Morning</strong>: One full past paper, under time, in silent conditions. Then mark it slowly, reading every mark-scheme comment.</p>
<p><strong>Afternoon</strong>: Rest. Genuinely rest. A walk, a nap, food. No maths.</p>
<p><strong>Evening</strong>: 45 minutes MAX with the formula sheet. Cover the RHS of each identity or formula, write it from memory, check.</p>
<h2>T-24 hours (Sunday)</h2>
<p><strong>Morning</strong>: One easy paper — pick a topic you're strong on. This is confidence building, not learning.</p>
<p><strong>Afternoon</strong>: The final formula-sheet pass. Anything you still get wrong, write on an index card and keep in your pocket.</p>
<p><strong>Evening</strong>: NO MATHS. Lay out clothes, calculator, spare pens, ID card. Set two alarms. In bed by 22:30.</p>
<h2>The morning of</h2>
<p><strong>Wake time</strong>: at least 90 minutes before you need to leave. This gives your prefrontal cortex time to boot up.</p>
<p><strong>Breakfast</strong>: complex carbs + protein (oats, eggs, banana). Avoid sugar spikes — they cause a 10:30 crash right in the middle of the paper.</p>
<p><strong>Water</strong>: bottle to the exam room if allowed.</p>
<p><strong>30 minutes before the paper</strong>: the index cards from Sunday. That's it. No new material.</p>
<h2>What NOT to do</h2>
<p><strong>Do not learn new topics.</strong> Every hour spent on a topic you didn't know before is an hour lost from stabilising what you did know.</p>
<p><strong>Do not compare with friends.</strong> They will claim, on the morning of, to have solved every past paper twice. They haven't. Ignore them.</p>
<p><strong>Do not caffeinate at 6 am.</strong> Your baseline is already elevated. Extra caffeine causes shakes in a 3-hour paper.</p>
<p><strong>Do not stay up "just to finish this one topic".</strong> Sleep improves recall by 15-30%. That's more than any topic revision.</p>
<h2>Between two papers (if applicable)</h2>
<p>If Paper 1 was Monday and Paper 2 is Thursday:</p>
<ul>
<li><strong>Monday evening</strong>: brief mental review of Paper 1 (max 20 minutes), then rest.</li>
<li><strong>Tuesday</strong>: full recovery day. One easy paper if you must — but rest is more valuable.</li>
<li><strong>Wednesday</strong>: same structure as T-24 above.</li>
</ul>
<p>Do NOT re-mark Paper 1 in detail on Monday evening. You cannot change it. All you'll do is worry about the questions that went wrong and drag that worry into Paper 2.</p>
<h2>The morning-of mindset</h2>
<p>Two sentences to say aloud in the mirror:</p>
<p>1. "I know more than I need to. I just have to access it cleanly."</p>
<p>2. "If I get stuck, I flag and move on."</p>
<p>That's it. Not "I'm going to smash this". Not "I hope I do well." Two operational statements that focus on execution.</p>
<h2>After the paper</h2>
<p>Do not talk about it with friends for at least 30 minutes. Everyone's memory of what was on the paper is already distorted by the emotion of the last hour. Give yourself space.</p>
<p>Then, if you have another paper coming, follow the between-papers plan. If you're done — done. Rest. Whatever mark comes, comes.</p>
<h2>The one-line summary</h2>
<p>Rest more, revise less, arrive rested. Everything else is noise.</p>

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      <title>Connected particles: pulley questions without tears</title>
      <link>https://alevelmathrevision.com/blog-alevel/connected-particles-pulleys.html</link>
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      <pubDate>Sat, 28 Mar 2026 09:00:00 +0000</pubDate>
      <description>Two objects, one string, one right method. The template that works for every M1 pulley question.</description>
      <category>Mechanics · M1</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/connected-particles-pulleys.jpg" alt="Connected particles: pulley questions without tears" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>Every M1 paper has a pulley question. Every one of them can be solved in four steps. Here is the template.</p>
<h2>The four-step template</h2>
<p><strong>Step 1</strong> — Draw two SEPARATE free-body diagrams, one for each particle. Same tension $T$ on both (same string), pointing INTO the string in each case.</p>
<p><strong>Step 2</strong> — Assume a direction of motion. Draw an acceleration arrow $a$ in that direction on BOTH diagrams. If you assumed wrong, $a$ comes out negative — no drama.</p>
<p><strong>Step 3</strong> — Write Newton's 2nd law for each particle, along the direction of motion.</p>
<p><strong>Step 4</strong> — Add or subtract the two equations to eliminate $T$; solve for $a$; back-substitute for $T$.</p>
<h2>The classic worked example</h2>
<p>Two masses, 4 kg and 6 kg, connected by a light string over a smooth pulley. The 6 kg is falling. Find $a$ and $T$.</p>
<p><strong>Step 1</strong> — Two diagrams. On the 4 kg: $T$ up, $4g$ down. On the 6 kg: $T$ up, $6g$ down.</p>
<p><strong>Step 2</strong> — Motion: 6 kg falls, 4 kg rises. Both accelerate with the same magnitude $a$.</p>
<p><strong>Step 3</strong> — Newton's 2nd law:</p>
<ul>
<li>6 kg (down positive): $6g - T = 6a$</li>
<li>4 kg (up positive): $T - 4g = 4a$</li>
</ul>
<p><strong>Step 4</strong> — Add:</p>
<p>$2g = 10a \Rightarrow a = \dfrac{g}{5} = 1.96 \text{ m s}^{-2}$</p>
<p>Back-substitute:</p>
<p>$T = 4g + 4a = 4(9.8) + 4(1.96) = 47.04 \text{ N}$</p>
<p>Done.</p>
<h2>The variations</h2>
<p><strong>One block on a horizontal table, one hanging over the edge.</strong> Table block has $T$ pulling it toward the pulley; hanging block has $T$ upward, $mg$ downward. Same template. Include friction on the table block if the surface is rough.</p>
<p><strong>One block on an inclined plane, one hanging.</strong> Inclined block has $T$ up the slope, weight component $mg\sin\theta$ down the slope, friction $\mu R$ opposing motion. Everything else is identical.</p>
<p><strong>Both blocks on inclined planes (Atwood variant).</strong> Two slopes meeting at a peak, string over the peak. Each block has $T$ up its slope, $mg\sin\theta$ down its slope. Same template, two slope angles.</p>
<h2>The common traps</h2>
<p><strong>Tension isn't $mg$.</strong> Students routinely write $T = mg$ for the hanging block and then can't reconcile with the falling block. If a block accelerates, $T \ne mg$. That's the whole point.</p>
<p><strong>Same tension throughout.</strong> A light, inextensible string transmits the SAME tension along its length. Both diagrams get the SAME $T$. Different tensions means the string is stretching or the pulley isn't smooth — a different question.</p>
<p><strong>Sign of acceleration.</strong> Pick a direction, stick to it on both diagrams. If your $a$ comes out negative, the motion is opposite to what you assumed — but the magnitude is correct. Don't restart.</p>
<h2>Your drill</h2>
<p>Find three pulley questions from past M1 papers. Time yourself. Aim for under 6 minutes per question, including the two diagrams.</p>
<p>By the third question, you'll notice the four steps are the same every time. Only the free-body forces change. That's the pattern — commit to it and pulleys stop being a "topic" and become a template.</p>

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      <title>IAL P4 vectors: the 3D geometry checklist</title>
      <link>https://alevelmathrevision.com/blog-alevel/ial-p4-vectors.html</link>
      <guid isPermaLink="true">https://alevelmathrevision.com/blog-alevel/ial-p4-vectors.html</guid>
      <pubDate>Wed, 25 Mar 2026 09:00:00 +0000</pubDate>
      <description>Lines, planes, angles, distances — the six exam-ready patterns and the formula each hangs on.</description>
      <category>IAL · P4</category>
      <dc:creator>Pete Bromfield</dc:creator>
      <enclosure url="https://alevelmathrevision.com/blog-alevel/images/ial-p4-vectors.jpg" length="99199" type="image/jpeg" />
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/ial-p4-vectors.jpg" alt="IAL P4 vectors: the 3D geometry checklist" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>IAL P4 vectors are entirely pattern-based. Once you know the six patterns Edexcel keeps testing, you can identify each question in ten seconds and go straight for the formula.</p>
<h2>The six patterns</h2>
<h3>1. Equation of a line through two points</h3>
<p>Given $A$ and $B$, the line is $\mathbf{r} = \mathbf{a} + t(\mathbf{b} - \mathbf{a})$.</p>
<p>Trap: writing the direction vector as $(\mathbf{a} + \mathbf{b})$ (that's the midpoint direction, meaningless here) or $(\mathbf{b} + \mathbf{a})$ order. It's always $(\mathbf{b} - \mathbf{a})$.</p>
<h3>2. Angle between two lines</h3>
<p>Direction vectors $\mathbf{d}_1$ and $\mathbf{d}_2$:</p>
<p>$$\cos\theta = \dfrac{|\mathbf{d}_1 \cdot \mathbf{d}_2|}{|\mathbf{d}_1||\mathbf{d}_2|}$$</p>
<p>The modulus in the numerator ensures the answer is the acute angle. Miss the modulus and you get the obtuse — and lose the mark.</p>
<h3>3. Point of intersection of two lines</h3>
<p>Set the two vector equations equal, giving three scalar equations in two parameters ($s$ and $t$). Solve any TWO for $s$ and $t$; verify with the third. If the third fails, the lines are skew.</p>
<p>Trap: not verifying with the third equation. Examiners award a mark specifically for "checks that lines intersect".</p>
<h3>4. Shortest distance from a point to a line</h3>
<p>Point $P$, line $\mathbf{r} = \mathbf{a} + t\mathbf{d}$. The shortest distance is:</p>
<p>$$d = \dfrac{|(\mathbf{p} - \mathbf{a}) \times \mathbf{d}|}{|\mathbf{d}|}$$</p>
<p>Cross product on top, magnitude of direction on bottom.</p>
<h3>5. Equation of a plane through three points</h3>
<p>Three points $A, B, C$. The normal to the plane is $\mathbf{n} = (\mathbf{b} - \mathbf{a}) \times (\mathbf{c} - \mathbf{a})$. Then the plane is $\mathbf{r} \cdot \mathbf{n} = \mathbf{a} \cdot \mathbf{n}$.</p>
<h3>6. Angle between a line and a plane</h3>
<p>Direction vector $\mathbf{d}$, plane normal $\mathbf{n}$. The angle $\alpha$ between the line and the plane is the COMPLEMENT of the angle between $\mathbf{d}$ and $\mathbf{n}$:</p>
<p>$$\sin\alpha = \dfrac{|\mathbf{d} \cdot \mathbf{n}|}{|\mathbf{d}||\mathbf{n}|}$$</p>
<p>Note the SINE, not cosine. If you use cosine you get the angle to the normal, which is $90° - \alpha$.</p>
<h2>The unified worked example</h2>
<p>Given $A(1, 2, -1)$, $B(3, 0, 5)$, and the plane $\Pi$: $2x - y + z = 4$.</p>
<p><strong>(a) Line through $A$ and $B$</strong>: $\mathbf{r} = (1, 2, -1) + t(2, -2, 6)$.</p>
<p><strong>(b) Angle line makes with plane</strong>: $\mathbf{d} = (2, -2, 6)$, $\mathbf{n} = (2, -1, 1)$.</p>
<p>$\mathbf{d} \cdot \mathbf{n} = 4 + 2 + 6 = 12$; $|\mathbf{d}| = \sqrt{44}$; $|\mathbf{n}| = \sqrt{6}$.</p>
<p>$\sin\alpha = \dfrac{12}{\sqrt{44}\sqrt{6}} = \dfrac{12}{\sqrt{264}} \approx 0.738$; $\alpha \approx 47.6°$.</p>
<p><strong>(c) Point of intersection</strong>: substitute the line's parametric form into the plane equation.</p>
<p>$2(1+2t) - (2-2t) + (-1+6t) = 4$</p>
<p>$2 + 4t - 2 + 2t - 1 + 6t = 4$</p>
<p>$12t = 5 \Rightarrow t = \dfrac{5}{12}$.</p>
<p>Point: $\left(\dfrac{22}{12}, \dfrac{14}{12}, \dfrac{18}{12}\right) = \left(\dfrac{11}{6}, \dfrac{7}{6}, \dfrac{3}{2}\right)$.</p>
<h2>Your drill</h2>
<p>Print the six formulae. For every past-paper vectors question you attempt, write which pattern it is BEFORE you start working. If you can name the pattern in under 10 seconds, you'll finish the question in under 5 minutes.</p>
<p>The whole P4 vectors section — often 12-14 marks — becomes a question of naming, not thinking.</p>

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      <title>Parametric equations: the sketching trick that saves 10 minutes in Paper 2</title>
      <link>https://alevelmathrevision.com/blog-alevel/parametric-equations-sketching.html</link>
      <guid isPermaLink="true">https://alevelmathrevision.com/blog-alevel/parametric-equations-sketching.html</guid>
      <pubDate>Sat, 21 Mar 2026 09:00:00 +0000</pubDate>
      <description>Most students plot 20 points. You only need 5, if you know which. Full worked example inside.</description>
      <category>UK 9MA0 · Pure</category>
      <dc:creator>Pete Bromfield</dc:creator>
      <enclosure url="https://alevelmathrevision.com/blog-alevel/images/parametric-equations-sketching.jpg" length="129465" type="image/jpeg" />
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/parametric-equations-sketching.jpg" alt="Parametric equations: the sketching trick that saves 10 minutes in Paper 2" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>Parametric equations appear in every UK 9MA0 Paper 2 and every IAL P4. The sketching part often carries 4-6 marks, and students routinely burn 15 minutes plotting 20 evenly-spaced $t$-values.</p>
<p>There's a better way. Five carefully-chosen points, joined with knowledge of the curve's behaviour, gets you the mark in under 4 minutes.</p>
<h2>The five points that matter</h2>
<p>Given $x = f(t)$ and $y = g(t)$:</p>
<ul>
<li><strong>Endpoints</strong> ($t = a$ and $t = b$, if the domain is stated).</li>
<li><strong>Any $t$ where $x$ turns around</strong>: solve $\dfrac{dx}{dt} = 0$.</li>
<li><strong>Any $t$ where $y$ turns around</strong>: solve $\dfrac{dy}{dt} = 0$.</li>
<li><strong>Any $t$ where $y = 0$</strong> (x-axis intercept).</li>
<li><strong>Any $t$ where $x = 0$</strong> (y-axis intercept).</li>
</ul>
<p>Between them, you'll capture every stationary point, every intercept, and every turning behaviour in the curve.</p>
<h2>Worked example</h2>
<p>Sketch $x = t^2 - 4$, $y = t^3 - 3t$ for $-2 \le t \le 2$.</p>
<p><strong>Step 1 — Endpoints.</strong></p>
<ul>
<li>$t = -2$: $(x, y) = (0, -2)$</li>
<li>$t = 2$: $(x, y) = (0, 2)$</li>
</ul>
<p><strong>Step 2 — Turning points of $x$.</strong></p>
<p>$\dfrac{dx}{dt} = 2t = 0 \Rightarrow t = 0$, giving $(-4, 0)$.</p>
<p><strong>Step 3 — Turning points of $y$.</strong></p>
<p>$\dfrac{dy}{dt} = 3t^2 - 3 = 0 \Rightarrow t = \pm 1$.</p>
<ul>
<li>$t = 1$: $(-3, -2)$</li>
<li>$t = -1$: $(-3, 2)$</li>
</ul>
<p><strong>Step 4 — Intercepts.</strong></p>
<ul>
<li>$y = 0$: $t^3 - 3t = 0 \Rightarrow t(t^2 - 3) = 0 \Rightarrow t = 0, \pm\sqrt{3}$. Only $t = 0$ is in range → $(-4, 0)$. (We already have this.)</li>
<li>$x = 0$: $t^2 - 4 = 0 \Rightarrow t = \pm 2$. Both already captured.</li>
</ul>
<p><strong>Step 5 — Join with knowledge.</strong></p>
<p>You now have six points. Sketch them. Then trace the curve by increasing $t$ from $-2$ to $2$ — the curve MOVES from $(0, -2)$ through $(-3, 2)$, through $(-4, 0)$, through $(-3, -2)$, ending at $(0, 2)$. That's a figure-eight-ish loop.</p>
<p>Total time: about 3 minutes.</p>
<h2>Why 20 points fails</h2>
<p>Plotting evenly spaced $t$-values misses the turning points unless you're lucky. You'll get the shape roughly right but you won't clearly show the stationary points — and the mark scheme awards a specific mark for identifying them.</p>
<h2>The Cartesian shortcut</h2>
<p>If you can eliminate $t$ and write the curve as $y = h(x)$ or $F(x, y) = 0$, do it. Many parametric curves become recognisable conics (ellipse, hyperbola) once eliminated.</p>
<p>For $x = 3\cos t$, $y = 2\sin t$: use $\cos^2 t + \sin^2 t = 1$ to get $\dfrac{x^2}{9} + \dfrac{y^2}{4} = 1$ — an ellipse. Sketch that in 30 seconds.</p>
<h2>Your practice drill</h2>
<p>Take three parametric-sketch questions from past papers. For each, work the five points ONLY — endpoints, dx/dt = 0, dy/dt = 0, intercepts. Time yourself. Aim for under 5 minutes per full sketch.</p>
<p>Do this every day for a week and Paper 2's parametric question stops being a 15-minute drain.</p>

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      <title>How to plan a two-hour Edexcel Maths paper: minute-by-minute</title>
      <link>https://alevelmathrevision.com/blog-alevel/planning-a-two-hour-paper.html</link>
      <guid isPermaLink="true">https://alevelmathrevision.com/blog-alevel/planning-a-two-hour-paper.html</guid>
      <pubDate>Wed, 18 Mar 2026 09:00:00 +0000</pubDate>
      <description>A time-map that survives contact with a real exam room — plus what to do when a question stumps you.</description>
      <category>Exam skills</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/planning-a-two-hour-paper.jpg" alt="How to plan a two-hour Edexcel Maths paper: minute-by-minute" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>Two hours. 100 marks. The maths inside your head is only half the battle — the other half is deciding, minute by minute, where to spend it. Here is a time-map that has survived hundreds of my students' exam rooms.</p>
<h2>The 3-phase split</h2>
<p><strong>Phase 1 (0-70 min): The steady pass.</strong>  Do every question you can do fluently, in order. Don't skip. Don't spend more than the mark-count in minutes on any one question (a 6-mark question gets 6 minutes, max).</p>
<p><strong>Phase 2 (70-95 min): The stuck-question pass.</strong>  Return to the questions you flagged. You now have 25 minutes for maybe 3-4 questions. Prioritise the highest-mark ones first.</p>
<p><strong>Phase 3 (95-120 min): The check + finish pass.</strong>  Any question you truly couldn't crack — write down a first line. Even a re-statement of the question with variable names earns method marks. Then check the whole paper.</p>
<h2>Per-minute breakdown</h2>
<ul>
<li><strong>0-2 min</strong>: Read the front page. Circle the total marks. Note calculator vs no-calculator.</li>
<li><strong>2-10 min</strong>: Question 1 (usually 5-7 marks, algebra warmup).</li>
<li><strong>10-70 min</strong>: Steady pass at ~1 minute per mark.</li>
<li><strong>70-95 min</strong>: Flagged questions. Set a hard 6-minute cap per question.</li>
<li><strong>95-115 min</strong>: Finish everything you can, even with partial working.</li>
<li><strong>115-120 min</strong>: Check. Not re-solve — CHECK. Sign errors. Wrong-way-round differentiation. Calculator misreads.</li>
</ul>
<h2>The 90-second decision rule</h2>
<p>If you've been on a question for 90 seconds and you don't know your first move, FLAG IT and move on. Come back in Phase 2. This is the single hardest thing to learn, and it's worth more marks than any topic revision.</p>
<h2>What to do when a question stumps you</h2>
<p><strong>Read it again, slowly.</strong> Half the "stumps" are misreads. What is it asking? Circle the command word ("find", "show that", "prove", "hence"). Underline the given.</p>
<p><strong>Write down what you have.</strong> Even before you know the plan, write "given: $y = 2x^3 + \ldots$, need: value of $x$ where $\frac{dy}{dx} = 0$". You've just earned a knowledge mark for stating the given, and the act of writing usually unsticks you.</p>
<p><strong>Look for the topic.</strong> Every A-Level Maths question comes from one of 8-10 topic buckets. Which bucket is this? Which method for that bucket haven't you tried?</p>
<p><strong>Move on before the 6-minute cap.</strong> Come back in Phase 2 with a fresh brain.</p>
<h2>The "hence" trap</h2>
<p>When a question part says "hence" or "hence, or otherwise", the examiner is telling you: use the result of the PREVIOUS part. If you're stumped, look back one part. The answer to (a) is almost certainly the launchpad for (b).</p>
<h2>The "show that" trap</h2>
<p>"Show that $x = 3$" means you MUST arrive at $x = 3$ by legitimate working. If you can't get there — but a subsequent part uses $x = 3$ — that subsequent part is still worth full marks. Write "assuming $x = 3$" and continue.</p>
<h2>Your rehearsal plan</h2>
<p>Two weeks before the real exam, do a full paper under strict time. But afterwards — and this is the point — annotate WHEN you did each question. Which ones went past their mark-count minute? Which ones took 90 seconds to start? Adjust your Phase 1 order for the real paper based on this data.</p>
<p>Do this twice more. By the third rehearsal, your plan is muscle memory — and two hours becomes just enough.</p>

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      <title>Hypothesis testing at A-Level: the wording that gets full marks</title>
      <link>https://alevelmathrevision.com/blog-alevel/hypothesis-testing-wording.html</link>
      <guid isPermaLink="true">https://alevelmathrevision.com/blog-alevel/hypothesis-testing-wording.html</guid>
      <pubDate>Sat, 14 Mar 2026 09:00:00 +0000</pubDate>
      <description>The exact phrasing Edexcel wants for H₀, H₁, and &quot;there is sufficient evidence&quot; — and the half-marks trap.</description>
      <category>Statistics</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/hypothesis-testing-wording.jpg" alt="Hypothesis testing at A-Level: the wording that gets full marks" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>Hypothesis testing is the topic where being 90% right earns you 50% of the marks. The maths is often trivial — plug into the calculator, get a p-value. But the *wording* around the maths is where the marks live, and it's remarkably strict.</p>
<p>Here's the phrasing template Edexcel examiners want, sentence by sentence.</p>
<h2>The template</h2>
<p><strong>Step 1 — State the hypotheses.</strong></p>
<ul>
<li>$H_0$: $\mu = 20$ (or whatever the claimed value is)</li>
<li>$H_1$: $\mu \neq 20$ (two-tailed) or $\mu > 20$ / $\mu < 20$ (one-tailed)</li>
</ul>
<p>Use $\mu$ for population means, $p$ for proportions. <strong>Never use $\bar{x}$ or the sample statistic in the hypotheses</strong> — that's the classic half-mark loss.</p>
<p><strong>Step 2 — State the significance level.</strong></p>
<p>"Test at the 5% significance level" or "Using $\alpha = 0.05$".</p>
<p><strong>Step 3 — Calculate the test statistic or p-value.</strong></p>
<p>Show the calculator input. Something like "$Z = \dfrac{22 - 20}{\sigma/\sqrt{n}} = 1.82$".</p>
<p><strong>Step 4 — Compare.</strong></p>
<p>Either "critical value $z_{crit} = 1.96$; since $1.82 < 1.96$..." OR "$p = 0.069 > 0.05$..."</p>
<p><strong>Step 5 — The killer sentence.</strong></p>
<p>This is where the marks live. The examiner wants this EXACT structure:</p>
<div class="callout">"There is <strong>insufficient / sufficient</strong> evidence to reject $H_0$. We <strong>cannot / can</strong> conclude, at the 5% level, that [restatement of $H_1$ in context]."</div>
<h2>The half-mark trap</h2>
<p>Students routinely write "<strong>We accept $H_0$</strong>" or "<strong>$H_0$ is true</strong>". Both lose the interpretation mark.</p>
<p>You can NEVER accept $H_0$. You either reject it or fail to reject it. And you can NEVER call it "true" — statistics is about evidence, not truth.</p>
<p>The other trap: not putting the conclusion in CONTEXT. If the question is about the mean weight of chocolate bars, your conclusion must mention chocolate bars. "We cannot reject $H_0$" alone earns partial marks; "We cannot conclude that the mean chocolate-bar weight differs from 20g" earns full marks.</p>
<h2>The one-tailed sign trap</h2>
<p>For a one-tailed test, the sign of $H_1$ matches the direction stated in the question. "The claim is that the mean has *increased*" → $H_1: \mu > 20$. Get this backwards and every subsequent mark cascades.</p>
<p>Read the question TWICE. Underline the direction. Write $H_1$ with the sign matching, then check by re-reading the underlined phrase.</p>
<h2>A worked example</h2>
<p>*A machine is claimed to produce bolts with mean length 5.0 cm. A sample of 25 bolts has mean 5.08 cm with population standard deviation 0.2 cm. Test at the 5% level whether the mean has changed.*</p>
<p>Full-marks answer:</p>
<ul>
<li>$H_0: \mu = 5.0$</li>
<li>$H_1: \mu \neq 5.0$ (<strong>two-tailed</strong> because "changed" is directionless)</li>
<li>Significance level $\alpha = 0.05$</li>
<li>Test statistic: $Z = \dfrac{5.08 - 5.0}{0.2/\sqrt{25}} = 2.0$</li>
<li>Critical values $\pm 1.96$; since $2.0 > 1.96$, we reject $H_0$.</li>
<li><strong>Conclusion</strong>: There is sufficient evidence, at the 5% level, that the mean bolt length has changed from 5.0 cm.</li>
</ul>
<p>Notice the conclusion restates the CONTEXT ("mean bolt length") and the DIRECTION of $H_1$ ("has changed"). That's the mark.</p>
<h2>Your drill</h2>
<p>Take any five hypothesis-testing questions from past papers. Write ONLY the conclusion sentence for each. Mark yourself against the mark scheme with brutal honesty — did you use "reject" / "fail to reject" AND put it in context? If not, rewrite the sentence until you do.</p>
<p>Five sentences a day for a week. Twelve marks recovered on the real paper.</p>

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      <title>Free-body diagrams: the drawing habit that unlocks 4 marks per Mechanics question</title>
      <link>https://alevelmathrevision.com/blog-alevel/mechanics-free-body-diagrams.html</link>
      <guid isPermaLink="true">https://alevelmathrevision.com/blog-alevel/mechanics-free-body-diagrams.html</guid>
      <pubDate>Wed, 11 Mar 2026 09:00:00 +0000</pubDate>
      <description>Examiners keep saying it — students who draw first score higher. Here&#x27;s the exact routine.</description>
      <category>Mechanics</category>
      <dc:creator>Pete Bromfield</dc:creator>
      <enclosure url="https://alevelmathrevision.com/blog-alevel/images/mechanics-free-body-diagrams.jpg" length="114751" type="image/jpeg" />
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/mechanics-free-body-diagrams.jpg" alt="Free-body diagrams: the drawing habit that unlocks 4 marks per Mechanics question" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>Every Edexcel examiner's report on Mechanics contains the same complaint: *"Students who did not draw a labelled diagram lost method marks that were freely available."* And yet, year after year, students skip the drawing step and go straight to $F = ma$.</p>
<p>Here is the exact three-line diagramming routine I make every one of my Mechanics students perform before they touch algebra.</p>
<h2>The three-line routine</h2>
<p><strong>Line 1 — The object.</strong> Draw a rectangle or circle. Label what it is (particle, block, sphere). Nothing else.</p>
<p><strong>Line 2 — Every force, arrowed and labelled.</strong> Weight, normal reaction, tension, friction, applied force, thrust — all of them. Point each arrow in the direction the force acts on the body. Label with the SYMBOL first ($W$, $R$, $T$), then the value in brackets if given.</p>
<p><strong>Line 3 — The axes.</strong> A tiny pair of arrows in the corner: one along the direction of motion (or expected motion), one perpendicular. Label them $\rightarrow$ and $\uparrow$ (or angled if it's a slope).</p>
<h2>Why this gets marks</h2>
<p>The mark scheme almost always includes a line like *"M1 for correct diagram / resolution attempt"*. That's an available mark BEFORE you've done any algebra. Miss the diagram, miss the mark.</p>
<p>Then, when you resolve, you're less likely to:</p>
<ul>
<li><strong>Forget a force.</strong> (Friction is the most-forgotten in inclined-plane questions.)</li>
<li><strong>Get a sign wrong.</strong> (Weight always points DOWN — students routinely reverse it on slopes.)</li>
<li><strong>Miss a component.</strong> (When a rope goes over a pulley, the tension pulls the block along the string, not straight up.)</li>
</ul>
<h2>Worked example — inclined plane, block sliding</h2>
<p>A block of mass 4 kg rests on a plane inclined at 30°. Coefficient of friction $\mu = 0.2$. Find the acceleration down the slope.</p>
<p><strong>Line 1</strong>: Draw the block on the slope.</p>
<p><strong>Line 2</strong>: Four forces — $W$ down, $R$ perpendicular to slope, $F$ (friction) up the slope, no applied force. Label each.</p>
<p><strong>Line 3</strong>: Axes: one down the slope ($x$), one perpendicular to slope ($y$).</p>
<p>Now resolve:</p>
<ul>
<li>Perpendicular: $R = W\cos 30° = 4g\cos 30°$</li>
<li>Parallel: $ma = W\sin 30° - \mu R = 4g\sin 30° - 0.2 \cdot 4g\cos 30°$</li>
<li>So $a = g(\sin 30° - 0.2\cos 30°) \approx 3.20 \text{ m s}^{-2}$</li>
</ul>
<p>If you'd started with $F = ma$ before the diagram, you'd probably have written $W$ as a pure downward force and lost the resolution mark.</p>
<h2>Two variations that catch students out</h2>
<p><strong>Pulley over a smooth peg.</strong> Two blocks connected by a string. Draw TWO free-body diagrams — one for each block — with the tension $T$ pointing INTO the string (upward for a hanging block, along the string for a resting block). Same $T$ on both diagrams.</p>
<p><strong>Rough contact between two blocks stacked vertically.</strong> The friction between them acts in OPPOSITE directions on the two blocks (Newton's third law). Students routinely draw them the same way. Draw the pair on the same page so you can eyeball the direction check.</p>
<h2>Your action plan</h2>
<p>For every Mechanics question you attempt from now until the exam:</p>
<p>1. Draw the diagram before you write any equation.</p>
<p>2. Tick each of the three lines aloud: "object, forces, axes".</p>
<p>3. Mark yourself against the mark scheme and check the diagram earned M1.</p>
<p>Three papers of this discipline and it becomes a reflex. And every M1 is a mark you'd otherwise have missed.</p>

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      <title>IAL Pure 1 in 5 hours: the minimum viable revision pass</title>
      <link>https://alevelmathrevision.com/blog-alevel/ial-p1-in-5-hours.html</link>
      <guid isPermaLink="true">https://alevelmathrevision.com/blog-alevel/ial-p1-in-5-hours.html</guid>
      <pubDate>Sat, 07 Mar 2026 09:00:00 +0000</pubDate>
      <description>One weekend before P1? Here&#x27;s what to do, in this order — nothing else earns marks quicker.</description>
      <category>IAL · P1</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/ial-p1-in-5-hours.jpg" alt="IAL Pure 1 in 5 hours: the minimum viable revision pass" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>You've been putting it off. There's a weekend. Nothing else works. Here is the exact 5-hour plan I give my Year 12 IAL students the Saturday before a P1 mock — and it consistently lifts them a grade boundary.</p>
<h2>Hour 1 — The formula sheet (60 minutes)</h2>
<p>Do NOT open a past paper yet. Print the Edexcel formula book. On a blank sheet, write out every P1 formula from memory. Cross-check against the printed one.</p>
<p>Every formula you got wrong — even a sign — write it three times on a fresh line. This is not busywork. Examiners routinely give a mark just for stating the correct formula before you use it.</p>
<h2>Hour 2 — Two hardcore quadratic questions (60 minutes)</h2>
<p>Pick two Paper 1 questions from the last two years that are pure quadratic manipulation — completing the square, discriminant, roots. Do them under exam conditions, no calculator.</p>
<p>Then, when the timer stops, mark yourself against the official mark scheme. <strong>Do not skip the mark scheme reading step.</strong> Every "A1 for correct" and "M1 for method" tells you what the examiner is looking at. Learn the language.</p>
<h2>Hour 3 — Coordinate geometry drill (60 minutes)</h2>
<p>Straight lines, midpoints, gradients, perpendicular bisectors, circles. This topic is 8-12 marks in P1 and mechanical if you know four things:</p>
<ul>
<li>Gradient formula</li>
<li>Midpoint formula</li>
<li>Line equation from a point + gradient</li>
<li>Circle equation $(x-a)^2 + (y-b)^2 = r^2$ and how to derive centre + radius from expanded form</li>
</ul>
<p>Do six mixed short questions from the topic bank. Speed matters here — under 4 minutes per question.</p>
<h2>Hour 4 — Differentiation basics (60 minutes)</h2>
<p>The rules ($\frac{d}{dx}(x^n) = nx^{n-1}$, sum, chain), then tangents and normals to a curve.</p>
<p>The archetype question: "Find the equation of the tangent to $y = f(x)$ at the point where $x = a$." Learn to execute this in under 3 minutes. Every P1 has at least one.</p>
<h2>Hour 5 — One full past paper, unmarked (60 minutes)</h2>
<p>Now — and only now — do a full past paper. Under time. No breaks, no reference materials, no phone. When the timer stops, stop.</p>
<p>Do not mark it tonight. Sleep on it. Mark it in the morning while you're fresh.</p>
<div class="callout"><strong>Why this order works.</strong> You're loading working-memory in the sequence the paper tests you. Formulas → algebra → coordinates → calculus → mixed. By the time you sit the real thing, the sequence is already grooved.</div>
<h2>What NOT to do</h2>
<ul>
<li><strong>Don't re-read your notes.</strong> Passive reading builds recognition, not recall. The exam demands recall.</li>
<li><strong>Don't do easy topics you already know.</strong> Every minute on something comfortable is a minute stolen from the topics that lose you marks.</li>
<li><strong>Don't watch YouTube.</strong> Not this weekend. Save it for a topic you can't crack after two attempts.</li>
</ul>
<p>Get the five hours right and you'll walk into Monday's mock feeling ready — not because you learnt everything, but because you learnt the RIGHT things in the right order.</p>

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      <title>The 12 pure identities every UK 9MA0 student must have on lockdown</title>
      <link>https://alevelmathrevision.com/blog-alevel/12-pure-identities-uk-9ma0.html</link>
      <guid isPermaLink="true">https://alevelmathrevision.com/blog-alevel/12-pure-identities-uk-9ma0.html</guid>
      <pubDate>Wed, 04 Mar 2026 09:00:00 +0000</pubDate>
      <description>The exact identities Paper 1 keeps testing — and the three most students fluff under time pressure.</description>
      <category>UK 9MA0 · Pure</category>
      <dc:creator>Pete Bromfield</dc:creator>
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      <content:encoded><![CDATA[<p><img src="https://alevelmathrevision.com/blog-alevel/images/12-pure-identities-uk-9ma0.jpg" alt="The 12 pure identities every UK 9MA0 student must have on lockdown" style="max-width:100%;height:auto;border-radius:8px;" /></p>
<div class="wrap" data-testid="post-body">
    <p>Every May, examiners write essentially the same identity questions. The command word changes, the surrounding context changes, but the underlying identity is one of twelve. Memorise these twelve — and know when to reach for each one — and you unlock 15-20 marks of easy points across Papers 1 and 2.</p>
<h2>The twelve you must know cold</h2>
<h3>Trigonometric (5)</h3>
<ul>
<li><strong>Pythagorean identity</strong>: $\sin^2\theta + \cos^2\theta \equiv 1$</li>
<li><strong>Tangent form</strong>: $\tan\theta \equiv \dfrac{\sin\theta}{\cos\theta}$</li>
<li><strong>Secant Pythagorean</strong>: $1 + \tan^2\theta \equiv \sec^2\theta$</li>
<li><strong>Cosecant Pythagorean</strong>: $1 + \cot^2\theta \equiv \csc^2\theta$</li>
<li><strong>Double-angle for cosine</strong>: $\cos 2\theta \equiv 1 - 2\sin^2\theta \equiv 2\cos^2\theta - 1$</li>
</ul>
<h3>Logarithm and exponent (4)</h3>
<ul>
<li><strong>Log product</strong>: $\log_a(xy) \equiv \log_a x + \log_a y$</li>
<li><strong>Log quotient</strong>: $\log_a(x/y) \equiv \log_a x - \log_a y$</li>
<li><strong>Log power</strong>: $\log_a(x^n) \equiv n\log_a x$</li>
<li><strong>Change of base</strong>: $\log_a x \equiv \dfrac{\log_b x}{\log_b a}$</li>
</ul>
<h3>Algebra (3)</h3>
<ul>
<li><strong>Difference of squares</strong>: $a^2 - b^2 \equiv (a-b)(a+b)$</li>
<li><strong>Sum of cubes</strong>: $a^3 + b^3 \equiv (a+b)(a^2 - ab + b^2)$</li>
<li><strong>Binomial-style</strong>: $(a+b)^2 \equiv a^2 + 2ab + b^2$</li>
</ul>
<h2>The three that go wrong most often</h2>
<p><strong>1. Sign flip on double-angle cosine.</strong> Students remember $\cos 2\theta \equiv 2\cos^2\theta - 1$ but write $1 - 2\cos^2\theta$ under pressure. Whenever you use this identity, circle the "1" and write the sign next to it before touching anything else.</p>
<p><strong>2. Missing modulus on logs.</strong> When you divide through by a log, some students forget that $\log_a x$ is only defined for $x > 0$. In a "solve" question, always write the domain restriction next to the manipulation. Examiners award a mark for stating it.</p>
<p><strong>3. Change-of-base direction.</strong> The formula is $\log_a x = \dfrac{\log_b x}{\log_b a}$ — students routinely invert it. The base you're changing FROM stays on top; the base you're changing TO goes underneath. Say it out loud twice before you write.</p>
<h2>How to drill these</h2>
<p>Set a five-minute timer. Fold a piece of paper into twelve boxes, write only the LEFT-hand side of each identity, and hand-write the RIGHT-hand side without looking. Do this three days in a row and you'll have them for life.</p>
<h2>Where they show up in the paper</h2>
<p>Roughly a quarter of Paper 1 questions rely on one of these twelve identities somewhere in the working. In Q6-8 (worth 6-9 marks each), the identity is often the first step of the method. Get it wrong and every subsequent mark is at risk.</p>
<div class="callout"><strong>Examiner tip.</strong> In a "prove that" or "show that" question, you MUST show the identity being used as a separate step. Writing $\sin^2\theta + \cos^2\theta = 1$ on its own line — before rearranging — is worth a Method mark on its own.</div>
<h2>Your action plan</h2>
<p>Print the twelve identities. Stick them above your desk. For every past paper you attempt in the next four weeks, notice which identities you actually reach for. Add a tally next to each. By the end of the four weeks, you'll know exactly which of the twelve are your gaps — and that's what you drill in the final fortnight.</p>

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