Question

What is the derivative of `y=sec(tan(x))` ?

Answer 1

Answer, `y'=sec(tan(x))tan(tan(x))(sec^2(x))`

Solution :

If, `y=sec(f(x))`

then using chain rule, `y'=sec(f(x))tan(f(x))f'(x)`

In same way,

`y'=sec(tan(x))tan(tan(x))(tan(x))'`

`y'=sec(tan(x))tan(tan(x))(sec^2(x))`