Answer
See below.
Work Step by Step
$y=\arccos x$ means that $y$ is the angle between $0$ and $\pi$ whose $\cos$ equals $x$.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.