- Trigonometry. the angle, measured in radians, that has a cosine equal to a given number. Abbreviation: arc cos; Symbol: cos−1
Origin of arc cosine
First recorded in 1905–10
Also called inverse cosine.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- The inverse of the cosine function.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.