Answer:
The result of the integral is
Step-by-step explanation:
Polar coordinates:
In polar coordinates, we have that:
And
In this question:
Region in the first quadrant between the circles with center the origin and radii 3 and 4
First quadrant means that ranges between and
Between these circles means that r ranges between 3 and 4. So
Applying the inner integral:
Using substitution, with , and considering that the integral of the sine is minus cosine, we have:
Applying the outer integral:
Has no factors of , so the result is the constant multiplied by , and then we apply the fundamental theorem.
The result of the integral is