$\displaystyle \int _ {0} ^ {2} {} \int _ {0} ^ {\sqrt {2y-y ^ {2}}} {} \frac{x+y} {x ^ {2} +y ^ {2}} dxdy$ 의 값은?

• ①$\displaystyle \frac{1} {2} + \frac{\pi} {2}$
• ②$\displaystyle 1+ \frac{\pi} {2}$
• ③$1+ \pi$
• ④$\displaystyle \frac{1} {2} + \pi$