CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Find the value of cosπ5+cos2π5+cos6π5+cos7π5

Open in App
Solution

cosπ5+cos2π5+cos6π5+cos7π5

rearranging

=cosπ5+cos6π5+cos2π5+cos7π5
=cosπ5+cos(π+π5)+cos2π5+cos(π+2π5)
as cos(π+θ)=-cos θ

=cosπ5cos(π5)+cos2π5cos(2π5)=0

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Basic Operations
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon