Advertisements
Advertisements
Question
The principal value of the expression cos–1[cos (– 680°)] is ______.
Options
`(2pi)/9`
`(-2pi)/9`
`(34pi)/9`
`pi/9`
MCQ
Fill in the Blanks
Advertisements
Solution
The principal value of the expression cos–1[cos (– 680°)] is `(2pi)/9`.
Explanation:
cos–1[cos (– 680°)] = cos–1[cos (720° – 40°)]
= cos–1[cos (– 40°)]
= cos–1[cos (40°)]
= 40°
= `(2pi)/9`.
shaalaa.com
Is there an error in this question or solution?
