Don't know the steps in finding this derivative.
But the derivative is
Now simplify:
The answer is:
x / / 2 \ x\ 2*e | x 2*\-3 - 3*cot (3*x)/*e | (cot(3*x)) *|2*e *log(cot(3*x)) + -----------------------| \ cot(3*x) /
/ 2 2 \ x | / 2 \ / 2 \ / / 2 \\ | 2*e | 2 9*\1 + cot (3*x)/ 6*\1 + cot (3*x)/ | 3*\1 + cot (3*x)/| x | x 2*(cot(3*x)) *|18 + 18*cot (3*x) - ------------------ - ----------------- + 2*|-log(cot(3*x)) + -----------------| *e + log(cot(3*x))|*e | 2 cot(3*x) \ cot(3*x) / | \ cot (3*x) /
/ 3 2 3 2 / 2\ \ x | / 2 \ / 2 \ / 2 \ / / 2 \\ / 2 \ / / 2 \\ | / 2 \ / 2 \ | | 2*e | 2 / 2 \ 54*\1 + cot (3*x)/ 27*\1 + cot (3*x)/ 9*\1 + cot (3*x)/ | 3*\1 + cot (3*x)/| 2*x 108*\1 + cot (3*x)/ | 3*\1 + cot (3*x)/| | 2 6*\1 + cot (3*x)/ 9*\1 + cot (3*x)/ | x | x 2*(cot(3*x)) *|54 + 54*cot (3*x) - 108*\1 + cot (3*x)/*cot(3*x) - ------------------- - ------------------- - ----------------- - 4*|-log(cot(3*x)) + -----------------| *e + -------------------- + 6*|-log(cot(3*x)) + -----------------|*|-18 - log(cot(3*x)) - 18*cot (3*x) + ----------------- + ------------------|*e + log(cot(3*x))|*e | 3 2 cot(3*x) \ cot(3*x) / cot(3*x) \ cot(3*x) / | cot(3*x) 2 | | \ cot (3*x) cot (3*x) \ cot (3*x) / /