Given that x = ln(sec(2y)) find dy/dx

x = ln (sec (2y))

The chain rule states that d/dy f (g (y)) = f'(g(y)). g'(y)

Here g(y) = sec(2y) so g'(y) = 2.sec(2y).tan(2y)

And f(y) = ln (y) so f'(y) = 1 / y

Thus dx/dy = (1 / sec(2y)) . (2.sec(2y).tan(2y)) = 2.tan(2y)

DH
Answered by Dom H. Maths tutor

13113 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Solve the differential equation: dy/dx = 6x^2 + 4x + 9


The line AB has equation 3x + 5y = 7. Find the gradient of line AB.


Express 3cos(theta) + 5sin(theta) in the form Rcos(theta - alpha) where R and alpha are constants, R>0 and 0<alpha<90. Give the exact value of R and the value of alpha to 2dp.


A pot of water is heated to 100C and then placed in a room at a temperature of 18C. After 5 minutes, the pan temperature falls by 20C. Find the temperature after 10minutes.


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