Don't know the steps in finding this derivative.
But the derivative is
The answer is:
sin(4*x) /sin(4*x) \
x *|-------- + 4*cos(4*x)*log(x)|
\ x /
/ 2 \
sin(4*x) |/sin(4*x) \ sin(4*x) 8*cos(4*x)|
x *||-------- + 4*cos(4*x)*log(x)| - -------- - 16*log(x)*sin(4*x) + ----------|
|\ x / 2 x |
\ x /
/ 3 \
sin(4*x) |/sin(4*x) \ 48*sin(4*x) 12*cos(4*x) /sin(4*x) \ /sin(4*x) 8*cos(4*x) \ 2*sin(4*x)|
x *||-------- + 4*cos(4*x)*log(x)| - 64*cos(4*x)*log(x) - ----------- - ----------- - 3*|-------- + 4*cos(4*x)*log(x)|*|-------- - ---------- + 16*log(x)*sin(4*x)| + ----------|
|\ x / x 2 \ x / | 2 x | 3 |
\ x \ x / x /