$$$\operatorname{acos}{\left(- \frac{1}{2} \right)}$$$

$$$\operatorname{acos}{\left(- \frac{1}{2} \right)}$$$을(를) 구하시오.

$$$\operatorname{acos}{\left(- \frac{1}{2} \right)} = \frac{2 \pi}{3}\approx 2.094395102393195$$$A

$$$\operatorname{acos}{\left(- \frac{1}{2} \right)} = 120^{\circ}$$$A

그래프는 graphing calculator를 참고하세요.