Here's even another problem which we did in class. Assume S = integral

evaluate this integral SS(4 - x^2 - y^2)dxdy. R is the first quadrant sector of the circle x^2 + y^2 = 4 between the lines x=0 and y=x

0 <= r <= 2 and 0 <= theta <= pi/4

Where in the world did my teacher get these bounds?