Para encontrar o volum do sólido realizaremos os cálculos abaixo:

\(\begin{align} & \int_{0}^{\pi /3}{\int_{0}^{\pi }{f(x,y)}=\int_{0}^{\pi /3}{\int_{0}^{\pi }{f(x,y)}}} \\ & \int_{0}^{\pi /3}{\int_{0}^{\pi }{f(x,y)}}=\int_{0}^{\pi /3}{\int_{0}^{\pi }{\cos 3xdydx}} \\ & \int_{0}^{\pi /3}{\int_{0}^{\pi }{f(x,y)}}=\int_{0}^{\pi }{\left( y \right)_{0}^{\pi /3}\cos 3xdx} \\ & \int_{0}^{\pi /3}{\int_{0}^{\pi }{f(x,y)}}=\int_{0}^{\pi }{\left( \frac{\pi }{3} \right)\cos 3xddx} \\ & \int_{0}^{\pi /3}{\int_{0}^{\pi }{f(x,y)}}=\int_{0}^{\pi }{\left( \frac{\pi }{3} \right)\cos 3xddx} \\ & \int_{0}^{\pi /3}{\int_{0}^{\pi }{f(x,y)}}=\left( \frac{\pi }{3} \right)\left( \frac{\sin 3x}{3} \right)_{0}^{\pi } \\ & V=\left( \frac{\pi }{3} \right)\left( \frac{\sin 3x}{3} \right)_{0}^{\pi } \\ & V=0 \\ \end{align}\ \)

Portanto, o volume do sólido será V=0