the integral,and a picture of the graph of D
in the left corner you have the integral and below it the range D. the right side has the ranges i found.
Hi im having a hard time understanding something i saw another student do.
the question was solving a double integral in a certain range of D. i needed to use polar cordinates to do so.
i found that the range of teta is (pi/4)<= teta <=(pi/3). the person that solved this integral used 0 <=tetta<= (pi/12)
i know the answer is the same, but in other excerises it might not be. what am i doing wrong, or his he mistaken(he got a perfect score).
i dont need you to solve it, just explain if what i did was wrong, and why, thank you.
Your setup is right. I was not able to find the calculation of the integral in the picture.
Since the angle between $\pi/4$ and $\pi/3$ is $\pi/12$, by symmetry your friend's setup is also right, and the calculation becomes (marginally) simpler.
If the integrand involved both $r$ and $\theta$, your setup would still be right, but because of the breakdown of angular symmetry, the other approach would not be right.