Find the area of the surface. The part of the surface z = xy that lies within the cylinder x2 + y2 = 36.

Step-by-step explanation:

From the given information:

The domain D of integration in polar coordinates can be represented by:

D = {(r,θ)| 0 ≤ r ≤ 6, 0 ≤ θ ≤ 2π) &;

The partial derivates for z = xy can be expressed  as:

Thus, the area of the surface is as follows:

correct answer:

b.(19,-2)