Hi, I've spent the best part of the day trying to get beyond this point and my trawling searches of the internet have sadly turned up no answers.
I am trying to integrate the equation shown in the picture above, I thought about converting the sin^2/3 to its trigonometric identity, but the only examples I can find are for when power is 2 or more. Anyone got any ideas where I could look for inspiration? or better yet able to offer an explanation. This day has killed me