Question

How do you find the derivative for `f(x) = sin^2 x`?

Answer 1

The answer is `y=2sinxcosx=sin2x`

This function can be written as `f(x)=g(h(x))` where `g(x)=x^2` and `h(x)=sinx`.
The derivative of such function has to be calculated as
`[g(h(x))]'=g'[h(x)]*h'(x)`
`[g(h(x))]'=2sinx*cosx`
Now you can apply the double angle formula to write the answer as
`y=sin2x`