What is the derivative of ln(sec^2 (x))ln(sec2(x))?

1 Answer
Mar 10, 2018

The derivative is 2tanx2tanx.

Explanation:

We can rewrite using trigonometry and the logarithm laws:

y= ln(1/cos^2x) = ln(1) - ln(cos^2x) = 0 - ln((cosx)^2) = -2ln(cosx)y=ln(1cos2x)=ln(1)ln(cos2x)=0ln((cosx)2)=2ln(cosx)

Therefore by the chain rule

y' = -2(-sinx)/cosx = (2sinx)/cosx = 2tanx

Hopefully this helps!