`arccos(-1/2)` Evaluate the expression without using a calculator.

Asked on by enotes

Textbook Question

Chapter 4, 4.7 - Problem 15 - Precalculus (3rd Edition, Ron Larson).
See all solutions for this textbook.

1 Answer | Add Yours

loves2learn's profile pic

loves2learn | (Level 3) Salutatorian

Posted on

You need to find value for which cos equals `-1/2 ` . Using a unit circle, it can be determined that the answer is ` (2pi)/3 `

We’ve answered 319,654 questions. We can answer yours, too.

Ask a question