Is my second derivative for y = (sinx)^2 correct?

[physics=world]

1. y = (sinx)^2

Homework Equations

The Attempt at a Solution

i found the 1st deriviative... 2(sinx)(cosx)

and then the second derivative... (-2(sinx)^2) + (cosx)^2

i don't have the answer. so i wanted to know if this was right.

 

[hotvette]

Not quite. Take a closer look. What's the derivative of 2(x)(x)? Using your method it would be 3x.