Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. **There will be no changes to other Yahoo properties or services, or your Yahoo account.** You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

## Trending News

# find the exact value of cos (5pi/12)+cos(pi/12)?

i have to show work too!!

### 3 Answers

- AshLv 71 month ago
cos (5π/12) + cos(π/12)

= 2 cos {[(5π/12) + (π/12)]/2} cos{[(5π/12) - (π/12)]/2}

= 2 cos (π/4) cos (π/6)

= 2 *(1/β2) *(β3)/2

= β(3/2)

- rotchmLv 71 month ago
Hint: First, finish your past recent questions. That's just good netiquette and how you will learn.Β

- KrishnamurthyLv 71 month ago
cos (5pi/12) + cos (pi/12)

= (sqrt(3) - 1)/(2 sqrt(2)) + (1 + sqrt(3))/(2 sqrt(2))

= sqrt(6)/2

= 1.224744871391589049098642037352945695982973...