# Thread: Polar curves area question

1. ## Polar curves area question

I'm stuck on this question. I'm not sure what the lower and upper limits area.

Find the area of the region that lies inside both curves.

r = 1+cos(theta), r = 1-cos(theta)

Thanks.

2. I suggest you to do a graph. The area is given by $4\frac{1}{2}\int_0^\frac{\pi}{2}(1-\cos\theta)^2d\theta$.

3. Thanks for your help. I did draw out a graph but was still confused. How did you find the limits of integration?

4. Drawing out a graph or notice that $\cos x = \cos (2\pi - x)=-\cos (\pi+x)$. So $1-\cos \theta$ it's symmetrical with x-axis and $1+\cos \theta$ is $1-\cos \theta$ reflection with y-axis.