(Solved): As you may or may not remember from Calculus classes, the differential surface area in polar coordi ...

As you may or may not remember from Calculus classes, the differential surface area in polar coordinates is: $dA=rdrd?$ Use this information to prove that the area of a circle of radius $R$ is $?R^2$. Question 3: Consider the following: As you may or may not remember from Calculus classes, the differential volume in spherical coordinates is: $dV=r^2\sin ?drd?d?$ Use this information to prove that the volume of a sphere of radius $R$ is $\frac{4}{3}?R^3$.