Q: Find the volume of the solid based on the interior of the circle r = cos θ, and capped by the plane z=x.

Is the answer:

$\displaystyle \int\nolimits_{0}^{\pi } {d\theta }\int\nolimits_{0}^{\cos \theta } {rdr}\int\nolimits_{0}^{r\cos \theta } {dz} = \pi/8$ ?