P3 further differentiation adds the chain, product and quotient rules and the derivatives of , and the trig functions. Spot the structure first: a function of a function needs the chain rule, a product of two functions the product rule, and one function divided by another the quotient rule.
: differentiate the outside, keep the inside, multiply by the inside's derivative. .
The product rule
. . Factorise the answer: it makes stationary points easy to find.
The quotient rule
. .
Using dx/dy
. If , then , so .
Key formulas
Standard derivatives Learn it
Trig derivatives In the formula booklet
Product; chain Learn it
Quotient In the formula booklet
Inverse Learn it
In the formula booklet = printed in Pearson's IAL formulae booklet, so know where to find it. Learn it = not printed there, so learn it by heart. All P3 formulas on one page (free PDF) →
P3 Further Differentiation worked examples
Each mark scheme is checked line by line before it is published here. M marks are for method, A marks for accurate answers that follow from them, B marks for independent results.
Worked example 1 · 5 marks · hard
A curve has the equation . Find the exact x-coordinate of the first positive turning point of the curve.
Mark scheme
M1 for using the product rule to differentiate: .
M1 for setting the derivative equal to 0 to find turning points: .
M1 for dividing by (since ) to get .
M1 for dividing by to obtain .
A1 for identifying the first positive solution as .
5 steps
Worked example 2 · 5 marks · hard
Find the equation of the normal to the curve at the point where . Give your answer in the form .
Mark scheme
M1 for finding the y-coordinate at : .
M1 for applying the product rule to find .
M1 for evaluating the gradient at : .
M1 for finding the perpendicular gradient of the normal: .
A1 for forming the equation and rearranging to .
5 steps
Worked example 3 · 4 marks · hard
Differentiate with respect to , giving your answer as a single algebraic fraction in its simplest form.
Mark scheme
M1 for correctly identifying and , and their derivatives and .
M1 for substituting into the quotient rule: .
M1 for factorising out in the numerator.
A1 for the correct simplified expression: .
4 steps
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Common P3 the chain, product and quotient rules mistakes
Forgetting the inner derivative., not .
The quotient rule's order. The numerator is ; swapping it changes the sign of the answer.
Product rule as a product of derivatives. is not .
Degrees on the calculator. Calculus with trig functions needs radians. Set the calculator to radians before substituting.
On our IAL formula sheet the quotient rule and the derivatives of tan, sec, cot and cosec are marked In the formula booklet; the chain and product rules and the derivatives of eˣ, ln x, sin and cos are marked Learn it.
Can I use the product rule instead of the quotient rule?
Yes: write u/v as u × v⁻¹ and use the product rule with the chain rule. The answer is the same, but you may need to simplify it to match the form a question asks for.
What are the usual chain rule slips?
Take y = (3x² + 1)⁴, whose derivative is 4(3x² + 1)³ × 6x = 24x(3x² + 1)³. The common wrong answers leave out the × 6x, differentiate 3x² as 3x instead of 6x, keep the power as 4 instead of reducing it to 3, or drop the + 1 inside the bracket. Write down the inner function u = 3x² + 1 and du/dx = 6x before you start.
Is a calculator allowed in IAL P3?
Yes. A calculator is allowed in every Edexcel IAL maths unit, P3 included. Method marks are for the working you write down, so show it.
How long is the IAL P3 exam?
Each IAL maths unit, P3 included, is one written paper of 1 hour 30 minutes worth 75 marks.
How often does the chain, product and quotient rules come up in P3?
In our mapping of the 4 Pearson P3 papers from June 2024 to June 2025, the chain, product and quotient rules was tested in 4 of them (7 questions in all). Any topic can be examined in any series.