_____________
/ 2
4*\/ 1 + cos (x)
4*sqrt(1 + cos(x)^2)
The derivative of a constant times a function is the constant times the derivative of the function.
Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
Differentiate term by term:
The derivative of the constant is zero.
Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
The derivative of cosine is negative sine:
The result of the chain rule is:
The result is:
The result of the chain rule is:
So, the result is:
Now simplify:
The answer is:
-4*cos(x)*sin(x) ---------------- _____________ / 2 \/ 1 + cos (x)
/ 2 2 \
| 2 2 cos (x)*sin (x)|
-4*|cos (x) - sin (x) + ---------------|
| 2 |
\ 1 + cos (x) /
----------------------------------------
_____________
/ 2
\/ 1 + cos (x)
/ 2 2 2 2 \
| 3*cos (x) 3*sin (x) 3*cos (x)*sin (x)|
4*|4 - ----------- + ----------- - -----------------|*cos(x)*sin(x)
| 2 2 2 |
| 1 + cos (x) 1 + cos (x) / 2 \ |
\ \1 + cos (x)/ /
-------------------------------------------------------------------
_____________
/ 2
\/ 1 + cos (x)