Integration Problem: Solve sin^3Φ from 0 to 2π

[ElDavidas]

It seems quite simple actually. But I'm still stuck:

$$\int_{0} ^ {2\Pi} sin^3\Phi d\Phi$$

Can anyone help?

 

[HallsofIvy]

That's a standard "sine or cosine to an odd power" integral.
$$sin^3\Phi d\Phi= (sin^2\Phi)(sin\Phi)d\Phi= (1- cos^2\Phi)(sin \Phi d\Phi)$$
See any simple substitution you can use?