Answer
c
Work Step by Step
The false statement is $\cos^{-1}(-\frac{1}{2})=-\frac{\pi}{3}$, because $-\frac{\pi}{3}$ is outside the range of the inverse cosine function.
The range of $\cos^{-1}x$ is $0\leq x\leq\pi$, and $-\frac{\pi}{3}$ does not belong to this range.
