y 2 = x , x = 2 y {\displaystyle y^{2}=x,x=2y} ∫ 0 2 π ( x = 2 y − x = y 2 ) {\displaystyle \int _{0}^{2}\pi (x=2y-x=y^{2})} = 64 p i 15 {\displaystyle ={\frac {64pi}{15}}}