Question

How do you find the derivative of `sin3x^2`?

Answer 1

With the chain rule.

Explanation:

I encourage who writes about mathematics to use always parenthesis to avoid confusion.

Is your expression `sin(3x^2)` or `sin(3x)^2`?
I assume it is the first. Then you calculate it applying the chain rule.

`d/dxsin(3x^2)=cos(3x^2)d/dx(3x^2)`

`=cos(3x^2)6x`.