y 2 = x , x = 2 y {\displaystyle y^{2}=x,x=2y}
∫ 0 4 π [ 2 y − y 2 ] d x = π [ 2 ( 4 ) − ( 4 ) 2 ] = π [ 8 − 16 ] {\displaystyle {\begin{aligned}\int _{0}^{4}\pi [2y-y^{2}]dx&=\pi [2(4)-(4)^{2}]\\[2ex]&=\pi [8-16]\\[2ex]\end{aligned}}}
= 64 p i 15 {\displaystyle ={\frac {64pi}{15}}}
![{\displaystyle {\begin{aligned}\int _{0}^{4}\pi [2y-y^{2}]dx&=\pi [2(4)-(4)^{2}]\\[2ex]&=\pi [8-16]\\[2ex]\end{aligned}}}](https://en.wikipedia.org/api/rest_v1/media/math/render/svg/3567500a071057f307a11ebd2bd99a81647177b0)
