ou may have learned in earlier calculus classes that the indefinite integral cannot be expressed using elementary functions, so we cannot compute it by hand. But there is a way to demonstrat that the integral. Begin by defining $.$

a$)$ Write I$^2$ as a double integral, and then convert to polar coordinates. Hint: The bounds of integration in polar coordinates will have one "endpoint" that is infinite. Should it be an endpoint of r or of theta.

b$)$ Evaluate the integral to find I$^2$ and conclude that $.$ This is very important result in probability and statistics.