# Thread: How did they get these bounds for this double integral?

1. ## How did they get these bounds for this double integral?

heres a problem from my textbook. How did they figure out those bounds for theta? On an exam i wont be able to use a calculator that graphs polar coords, and i should know how to do this anyways. Thanks

2. Originally Posted by Evan.Kimia
heres a problem from my textbook. How did they figure out those bounds for theta? On an exam i wont be able to use a calculator that graphs polar coords, and i should know how to do this anyways. Thanks

It's obvious where the bounds have come from. Are you asking how $\displaystyle x^2 + y^2 = 2x$ is converted to a polar equation?

3. I understand how the bounds for r are set by converting to polar coords but im not sure howe the bounds for theta (the -pi/2 to pi/2) are figured out.

4. Originally Posted by Evan.Kimia
I understand how the bounds for r are set by converting to polar coords but im not sure howe the bounds for theta (the -pi/2 to pi/2) are figured out.
The polar angle associated with (2, 0) is 0.

The polar angles associated with (0, 0) are -pi/2 and pi/2.