I want to convert some integrals to use polar coordinates as my differentials, my problem is getting the limits.
So this is the first concept I am not understanding: If I have a circle in the xy-plane and want to represent it in polar coordinates with the restriction that the region is strictly everything on the right hand side of the line $x=1$ why would the lower limit be $1/\cos(\theta)$ if the circle I have is $ (x-1)^2 +y^2 = 1 $. I sort of understand how to get the upper limit but not the theory behind the lower. For the upper I simply expanded the $x$ terms to get $ r^2 = 2r*cos(\theta)$ and solved to get an upper limit of $2\cos(\theta)$
Please could someone explain the theory about the lower limit.