Differentiate y=(x^2+5)^7

In this example instead of multiplying out 7 brackets it is useful to use the chain rule, which is used to differentiate the composition of more than one function. If we let what is inside the bracket equal u, then u=x^2+5, and y=u^7. The chain rule states that dy/dx=du/dxdy/du, so we simply differentiate both functions and multiply them: remembering that to differentiate x^n we do nx^(x-1), du/dx=2x (as constants disappear) and dy/du=7u^6. Therefore dy/dx=2x7u^6. Now all that is left is to plug the expression for u back in to get dy/dx=2x*7(x^2+5)^6, and simplify to get dy/dx=14x(x^2+5)^6. It is simplest to leave it in this form.

Answered by Rachel B. Maths tutor

4643 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

How do I solve this inequality: x^2>2x ?


Differentiate 2cos(x)sin(x) with respect to x


How do I solve equations with modulus functions on both sides?


What is the integral of sin^2(x)?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy