Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
Let .
The derivative of cosine is negative sine:
Then, apply the chain rule. Multiply by :
The derivative of a constant times a function is the constant times the derivative of the function.
Apply the power rule: goes to
So, the result is:
The result of the chain rule is:
The result of the chain rule is:
Now simplify:
The answer is:
-4*cos(2*x)*sin(2*x)
/ 2 2 \ 8*\sin (2*x) - cos (2*x)/
64*cos(2*x)*sin(2*x)