since sin(x-a) is a periodic function ,
0∫4pi f ( sin(x-a)) = 0-a∫4pi-a f( sin (x-a))
then x-a =t
\hspace{-16}\bf{\int_{0}^{4\pi}\ln\left|13.\sin (x)+3\sqrt{3}.\cos (x)\right|dx}=
Aditya, How did you do it? I'm getting stuck at this integral : 04Π∫ ln(sin (x+a)) dx , a ε C
since sin(x-a) is a periodic function ,
0∫4pi f ( sin(x-a)) = 0-a∫4pi-a f( sin (x-a))
then x-a =t