$\displaystyle \arctan \frac{\sqrt{3}} {2} + \arctan \frac{2} {\sqrt{3}}$ 의 값은?

• ①$\displaystyle \frac{\pi} {6}$
• ②$\displaystyle \frac{\pi} {4}$
• ③$\displaystyle \frac{\pi} {3}$
• ④$\displaystyle \frac{\pi} {2}$
• ⑤$\pi$