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