Chapter 13.3, Problem 23E

Cartesian to polar coordinates Sketch the given region of integration R and evaluate the integral over R using polar coordinates.

23.     ${\displaystyle \underset{R}{\iint }\left(x^2+y^2\right)dA;}$ R = {(r, θ): 0 ≤ r ≤ 4, 0 ≤ θ ≤ 2π}