IB Maths AA HL AA 5.1 Limits and differentiation questions

Exam-style questions in the shape of Paper 1 and Paper 2, with full markschemes. Read the markscheme, or type, photograph or draw your answer and get it marked.

Question 1

Paper 2, calculatorHard6 marks

Let nn be a fixed positive integer and let f(x)=xnf(x)=x^n where x∈Rx\in\mathbb R

(a)

Using the definition of the derivative from first principles, show that

f′(x)=nxn−1.f'(x)=nx^{n-1}.
[3]
(b)

For an integer rr with 1≤r≤n1\le r\le n prove that

f(r)(x)=n!(n−r)!xn−r.f^{(r)}(x)=\frac{n!}{(n-r)!}x^{n-r}.
[3]