I must find the area of the region that lies inside the first curve and outside the second curve for:
$ r^2 = 8cos2\theta, r = 2$
How do I find $a$ and $b$? My solution manual tells me that the curves intersect when $cos2\theta = 1/2$ but I don't see where that came from. I tried setting it equal to each other, but keep getting $1/4$.