I need help on calc 2

Question

what is derivative of 1/(ln(cosx))

Answer 1

y = 1/(ln(cosx))

 

It looks like multiple applications of the chain rule are needed to solve this one.

 

dy/dx = [- 1 / ln²(cosx)] [1/cosx] [-sinx] = [1 / ln²(cosx)] (sinx/cosx)

 

dy/dx = tanx / ln²(cosx)