Chapter 13.3, Problem 72E

Existence of integrals For what values of p does the integral ${\displaystyle \underset{R}{\iint }\frac{dA}{{\left(x^2+y^2\right)}^p}}$ exist in the following cases?

a.     $R=\left\{\left(r,\theta \right):1\le r<\infty ,0\le \theta \le 2\pi \right\}$

b.     $R=\left\{\left(r,\theta \right):0\le r\le 1,0\le \theta \le 2\pi \right\}$