함수 $\displaystyle f \left (x \right) = \frac{\pi} {3} x+ \arcsin x$ 에 대하여 $\displaystyle \left (f ^ {-1} \right) ' \left (\frac{\pi} {3} \right)$ 를 구하면?

• ①$\displaystyle \frac{3} {\pi +2 \sqrt {3}}$
• ②$\displaystyle \frac{3} {2 \pi -2 \sqrt {3}}$
• ③$\displaystyle \frac{3} {- \pi +2 \sqrt {3}}$
• ④$\displaystyle \frac{3} {\pi - \sqrt {3}}$
• ⑤$\displaystyle \frac{3} {\pi + \sqrt {3}}$