cos²5+c²10+cos²15+....+cos²85+cos²90 is equal to
Attachments:
Answers
Answered by
1
Step-by-step explanation:
cos²5 can be written as sin²(90-85)= sin²85
so now we can say sin²85+cos²85 =1
like that if we substitute values until cos²50
the answer will be 10
Answered by
2
Answer:
cos^2 5°+ sin^2 5° + cos^2 10° + Sin^2 10° .......cos^2 45°+ cos^2 90°
= 8+ 1/2
=17/2 as cos 90° = 0
Is there is an option of 17/2......?????????????
Because I can not see it.......
May I be right or not.......
Similar questions