Problem 2 (Stewart 15.3.40). Here is a very famous application of polar coordinates. (a) Evaluate the expression lim a -+ 00 Up ex-y dxdy where Da is the disk of radius a centered at (0, 0). That is, evaluate the integral in terms of a, and then compute the limit of the resulting expression. (b) Now consider the limit lim 6-+ 0o Us, ex -y dady where Sb is the square with opposite corners (-b, -b) and (b, b). Explain why this limit also exists and is equal to the answer from (a). Hint: Do not try to compute the integral in terms of b; it's impossible. Can you use the Squeeze Theorem somehow