to prove 4cos20 cos40 cos60 cos80 = 1/4 - Maths - Trigonometric Functions

Question

to prove 4cos20° cos40° cos60° cos80° = 1/4

Soons ☺😊 · Answer

Hope it helps:
<img src=
"https://s3mn%20mnimgs%20com/img/shared/content_ck_images/ck_5a8daf4a0bbba%20jpeg">

to prove 4cos20°.cos40°.cos60°.cos80° = 1/4