Question

How do you find the derivative of `y=ln(cosx^2)`?

Answer 1

`y = ln(cosx^2)`
`e^y=cos(x^2)`
`y'e^y=-2xsin(x^2)`
`y' = (-2xsin(x^2))/e^y`

but `e^y =cos(x^2)`

so

`y' = (-2xsin(x^2))/cos(x^2)`

`y' = -2xtan(x^2)`