cos(x)
--------
2
(x + 2)
cos(x)/(x + 2)^2
Apply the quotient rule, which is:
and .
To find :
The derivative of cosine is negative sine:
To find :
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.
Apply the power rule: goes to
The result is:
The result of the chain rule is:
Now plug in to the quotient rule:
Now simplify:
The answer is:
sin(x) (-4 - 2*x)*cos(x)
- -------- + -----------------
2 4
(x + 2) (x + 2)
4*sin(x) 6*cos(x)
-cos(x) + -------- + --------
2 + x 2
(2 + x)
-----------------------------
2
(2 + x)
24*cos(x) 18*sin(x) 6*cos(x)
- --------- - --------- + -------- + sin(x)
3 2 2 + x
(2 + x) (2 + x)
-------------------------------------------
2
(2 + x)