2 y*sin (y)
d / 2 \ --\y*sin (y)/ dy
Apply the product rule:
; to find :
Apply the power rule: goes to
; to find :
Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
The derivative of sine is cosine:
The result of the chain rule is:
The result is:
Now simplify:
The answer is:
2 sin (y) + 2*y*cos(y)*sin(y)
/ / 2 2 \ \ 2*\- y*\sin (y) - cos (y)/ + 2*cos(y)*sin(y)/
/ 2 2 \ 2*\- 3*sin (y) + 3*cos (y) - 4*y*cos(y)*sin(y)/