Given that x=ln(t) and y=4t^3,a) find an expression for dy/dx, b)and the value of t when d2y/dx2 =0.48. Give your answer to 2 decimal place.

a) Firstly, differentiate x and y with respect to t. 

Giving you dx/dt = 1/t       and dy/dt = 12t2

dy/dx is found using the chain rule:

dy/dx = dy/dt x dt/dx = 12t3

b) You will need to differentiate dy/dx again with respect to t, to do this:

d2y/dx2=36t2 x dt/dx = 36t3

36t3=0.48

t=(0.48/36)1/3

t=0.24

Answered by Sara W. Maths tutor

3001 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find the integral of [ 2x^4 - (4/sqrt(x) ) + 3 ], giving each term in its simplest form


I struggle with integration, and don't understand why we need to do it


Integrate ∫sin²xcosxdx


Calculate dy/dx of the following equation: y = 3x^3 - 6x^2 + 2x - 6


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 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences