Question

How do you find the derivative of these problems?:
h(x)=sin(2x)cos(2x)
f(x)=cot(x)/(sin(x))
y=4sec^2x

Answer 1

Product rule and quotient rule.

Answer 2

(oh, and chain rule too)

Answer 3

Yeah, but I'm having trouble using them to solve these. So for the first problem, this is what I did:
h(x)=sin(2x)cos(2x)
h'(x)=cos(2x)(cos(2x))(2)+(-sin(2x))(sin(2x)(2)
That's as far as I made it to.

Answer 4

and that's right

Answer 5

now simplify

Answer 6

I don't know how to simplify this though...

Answer 7

sin(u) * sin(u) = sin^2(u)

Answer 8

For the second one, remember that cot(u) = cos(u)/sin(u).