I have been struggling for a while on evaluating this definite infinite product integral:
This is a question given by my maths teacher a while back and I have been struggling with it ever since. I have tried so many different substitutions and I have even tried integrating by parts (do NOT do this), but nothing has led me even close to an answer. I'm guessing there is trig identity I must be missing in order to simplify the inside of the integral? or some wonder substitution?
Any help would be greatly appreciated.