You can use the product rule straight-away:
I need help finding the derivative of:
I believe I have to use the half angle identity...
if this is true, then would it be:
1/2 (1-cos(2x)) ?
would I need to take the derivative of this after the identity?
If this holds true, would be 2sin(2x) ???
But I would have done this using the chain rule directly- Let u= sin(x) and y= u^2= sin^2(x). Then .
Or, more simply, since the derivative of is 2x, the derivative of is 2x, the derivative of is 2 sin(x) times the derivative of sin(x), which is cos(x).
Of course, those are the same answer- sin(2x)= 2 sin(x)cos(x).