2 (z - 2*pi) ----------- cos(z) - 1
(z - 2*pi)^2/(cos(z) - 1)
Apply the quotient rule, which is:
and .
To find :
Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
Differentiate term by term:
Apply the power rule: goes to
The derivative of the constant is zero.
The result is:
The result of the chain rule is:
To find :
Differentiate term by term:
The derivative of the constant is zero.
The derivative of cosine is negative sine:
The result is:
Now plug in to the quotient rule:
Now simplify:
The answer is:
2
-4*pi + 2*z (z - 2*pi) *sin(z)
----------- + ------------------
cos(z) - 1 2
(cos(z) - 1)
/ 2 \
2 | 2*sin (z) |
(z - 2*pi) *|----------- + cos(z)|
\-1 + cos(z) / 4*(z - 2*pi)*sin(z)
2 + ---------------------------------- + -------------------
-1 + cos(z) -1 + cos(z)
------------------------------------------------------------
-1 + cos(z)
/ 2 \ / 2 \
| 2*sin (z) | 2 | 6*cos(z) 6*sin (z) |
6*sin(z) + 6*(z - 2*pi)*|----------- + cos(z)| + (z - 2*pi) *|-1 + ----------- + --------------|*sin(z)
\-1 + cos(z) / | -1 + cos(z) 2|
\ (-1 + cos(z)) /
-------------------------------------------------------------------------------------------------------
2
(-1 + cos(z))