© examsiri.com
Question : 157 of 160
Marks:
+1,
-0
Solution:
cos‌‌cos‌‌cos‌‌cos‌‌=cos‌24∘‌cos‌48∘‌cos‌96∘‌cos‌168∘‌=−cos‌12∘‌cos‌24∘‌cos‌48∘‌cos‌96∘‌=−‌| 16sin‌12∘ |
| 16sin‌12∘ |
‌cos‌12∘‌cos‌24∘‌cos‌48∘‌cos‌96∘‌=‌| −8sin‌24∘‌cos‌24∘‌cos‌48∘‌cos‌96∘ |
| 16sin‌12∘ |
‌=‌| −4sin‌48∘‌cos‌48∘‌cos‌96∘ |
| 16sin‌12∘ |
‌=−‌| 2sin‌96∘‌cos‌96∘ |
| 16sin‌12∘ |
‌=−‌| sin‌192∘ |
| 16sin‌12∘ |
=‌=‌
© examsiri.com
Go to Question: