am stuck on the integration part, so far I have

x = cost , y = sint

dx = -sint dt dy = cost dt

$\displaystyle \int ( xy^{2}) dx + ( x^{2}y + 2x) dy $ subbing in the values for x,y, dx and dy

i get

$\displaystyle \int^{2\pi}_{0} ( -cost sin^{3}t + cos^{3}t sint + 2cos^{2}t ) dt $

how do I simply / integrate this expression ?