Given f(x)=2x^3 - 2x^2 + 8x, find f'(x) and f"(x).

The first step in scoring full marks on this typically 4 mark question is to recognise what it's asking you to do. We use the process of differentiation to solve it. f(x)=2x^3 - 2x^2 + 8xf'(x) = 6x^2 - 4x + 8 as we multiply coefficients by the corresponding power of x and then reduce the power by 1. This also leaves the final term as a constant term without an x. The general rule we use is f'(x) = (na)x^(n-1) where our original equation has the form f(x) = ax^n.Using a similar method for f"(x) where the question asks us to differentiate again to find the second derivative, we find f"(x) = 12x - 4.

Answered by Maths tutor

4131 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Do the following vector equations intersect? l = (1 + μ)i + (2 - μ)j + (2μ - 5)k, and m = 2λi + 3j + (2 + λ)k.


Find the equation of the tangent for x = 2cos (2y +pi)


Using the sum, chain and product rules, differentiate the function f(x) = x^n +x^3 * sin(1/[3x])


Find integers A and B, such that (5x +4)/((2-x)(1+3x)) = A/(2-x) + B/(1+3x)


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning