Write a brief review of integrals in spherical polar coordinates
∫ 0 2 π ∫ 0 π ∫ 0 ∞ e − r r 3 sin θ d r d θ d ϕ {\displaystyle \int _{0}^{2\pi }\int _{0}^{\pi }\int _{0}^{\infty }e^{-r}r^{3}\sin \theta ~{\textrm {d}}r~{\textrm {d}}\theta ~{\textrm {d}}\phi }
