Question is: Using polar coordinates, evaluate the integral $\iint\sin(x^2+y^2)dA$ where R is the region $1\le x^2+y^2\le81$
My work for the inside integral, using bounds 1 to 9, was a constant:
Does this mean I can conclude my answer is this constant? In other words, can I bring it out of the integral with respect to theta from 0 to 2$\pi$? I am guessing not because my answer was not correct. If not, could someone explain why?