2 cos (7*x)
d / 2 \ --\cos (7*x)/ dx
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:
-14*cos(7*x)*sin(7*x)
/ 2 2 \ 98*\sin (7*x) - cos (7*x)/
2744*cos(7*x)*sin(7*x)