What is cos -1 ( -1/2) in quadrant 1 ?

Answer:
[tex]\frac{2\pi}{3}[/tex]
Step-by-step explanation:
So here they are asking for one angle that gives you the cosine value is equal to -1/2 while being in quadrant 2.
So you look in quadrant 2 and find x=-1/2 which is at [tex]\frac{2\pi}{3}[/tex].
[tex]\cos^{-1}(\frac{-1}{2})=\frac{2\pi}{3}[/tex] while being in quadrant 2.