Evaluate the given integral by changing to polar coordinates. Integar sin(x2 + y2) dA R
where R is the region in the first quadrant between the circles with center the origin and radii 1 and 5.

In polar coordinate, R is the set of points

{(r, θ) | 1 < r < 5 and 0 < θ < π/2}

So the integral is

(where s = r ²)

well if he bought them at 5 cedis each sold them at 7 cedis each then he would make a profit of 2 cedis of each book. if in total he made 150 cedis profit that means he sold 75 books. he lost 12 books at the start so that means he originally bought a total of 82 books.

step-by-step explanation: