1) $\displaystyle \begin{align*} V = \pi \int_0^2{ \left( x^2 \right) ^2 \, dx } \end{align*}$

2) $\displaystyle \begin{align*} V = \pi \int_0^4{ 2^2 - \left( \sqrt{y} \right) ^2 \, dy } \end{align*}$

3) $\displaystyle \begin{align*} V = \pi \int_0^2{ \left( x^2 + 3 \right) ^2 \, dx } \end{align*}$

4) $\displaystyle \begin{align*} V = \pi \int_0^4{ \left( 3 - \sqrt{y} \right) ^2 - 1^2 \, dy} \end{align*}$