정적분 $\displaystyle \int _ {0} ^ {\frac{1} {2}} {\frac{x ^ {3} +x} {\left (x ^ {2} -1 \right) ^ {3}} dx}$ 를 구하면?

• ①$\displaystyle - \frac{1} {9}$
• ②$\displaystyle - \frac{2} {9}$
• ③$\displaystyle - \frac{1} {3}$
• ④$\displaystyle - \frac{4} {9}$
• ⑤$\displaystyle - \frac{5} {9}$