Lemmara logoLemmaraWorked solution

WMA11/01 Jun 2025, Question 2: Differentiating Polynomials

Pearson Edexcel International AS Level Mathematics · Pure Mathematics 1 (WMA11) · Calculator · 5 marks

The question, in short

Curve C is y = 2x^(5/2) − 4x + 3. Differentiate it, then use the gradient 16 at point P with x-coordinate 2^k to find k.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 2 marks

Find dy/dx of y = 2x^(5/2) − 4x + 3 and give it in simplest form.

  1. 1d/dx(2x^(5/2)) = 2 × (5/2)x^(3/2) = 5x^(3/2)
  2. 2dy/dx = 5x^(3/2) − 4

Answerdy/dx = 5x^(3/2) − 4

Part (b) · 3 marks

At P, x = 2^k and the gradient is 16; find the value of k.

  1. 15x^(3/2) − 4 = 16, so x^(3/2) = 4
  2. 2x = 4^(2/3) = 2^(4/3)
  3. 32ᵏ = 2^(4/3), so k = 4/3

Answerk = 4/3

Stuck on a step? Read the free lesson: Differentiating Polynomials

Practise more differentiating polynomials questions

Real XMA01 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on differentiating polynomials

Also searched as: WMA11 June 2025 · WMA11/01 · wma11 jun25 · IAS Maths Pure Mathematics 1 June 2025 · question 2.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.