log(1 + cos(x))
d --(log(1 + cos(x))) dx
Let .
The derivative of is .
Then, apply the chain rule. Multiply by :
Differentiate term by term:
The derivative of the constant is zero.
The derivative of cosine is negative sine:
The result is:
The result of the chain rule is:
The answer is:
-sin(x) ---------- 1 + cos(x)
/ 2 \ | sin (x) | -|---------- + cos(x)| \1 + cos(x) / ----------------------- 1 + cos(x)
/ 2 \ | 3*cos(x) 2*sin (x) | |1 - ---------- - -------------|*sin(x) | 1 + cos(x) 2| \ (1 + cos(x)) / --------------------------------------- 1 + cos(x)