# How do you evaluate cos^-1(cos((11pi)/6))?

$\frac{11 \pi}{6}$
Use $\left[{\cos}^{- 1} \cos\right]$ is unit operator that returns the operand as the
Here the operand is $\frac{11 \pi}{6}$, and so, the answer is $\frac{11 \pi}{6}$.