2
x *8*cos(4*x)
-------------
5
((x^2*8)*cos(4*x))/5
The derivative of a constant times a function is the constant times the derivative of the function.
The derivative of a constant times a function is the constant times the derivative of the function.
Apply the product rule:
; to find :
Apply the power rule: goes to
; to find :
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 is:
So, the result is:
So, the result is:
Now simplify:
The answer is:
2
32*x *sin(4*x) 16*x*cos(4*x)
- -------------- + -------------
5 5
/ 2 \
16*\-8*x*sin(4*x) - 8*x *cos(4*x) + cos(4*x)/
---------------------------------------------
5