Given $\displaystyle r=\cos(\theta)$ and $\displaystyle r=\sin(\theta)$ find the area inside both circle.

Graphing it out gave me two that intersect in the first quadrant, now I was thinking that it would be

$\displaystyle \int_0^{\pi/2} \int_{\sin(\theta)}^{\cos(\theta)} r \ dr \ d\theta$

but this gives me $\displaystyle \frac{1}{8}$, whereas the solution in the back of the book tells me it's supposed to be $\displaystyle \frac{\pi-2}{8}$