# Math Help - [SOLVED] Critical points

1. ## [SOLVED] Critical points

if you solve f '(x)=(2sinx)(cosx)=0 ; how do you get that x=0
in case your wondering i am using the first derivative test and this is already the derivative of the original function which was f(x)=sin^2x

2. Originally Posted by vinson24
if you solve f '(x)=(2sinx)(cosx)=0 ; how do you get that x=0
in case your wondering i am using the first derivative test and this is already the derivative of the original function which was f(x)=sin^2x
not exactly sure what you mean ...

are you asking why $f'(x) = 0$, or are you asking how to solve $2\sin{x}\cos{x} = 0$ ?

3. im asking how to solve the equation (2sinx)(cosx)=0 so that you get x=0 as a critical point

4. You have either sin(x) = 0 or cos(x) = 0 so you know that x = 0 or x = Pi/2