Answer
$\approx0.51$
Work Step by Step
With a calculator in radian mode, use its inverse cosine function and round the result to two decimal places to obtain
$\cos^{-1}{\left(\frac{7}{8}\right)}\approx0.51$
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.