prove that-cos²A+cos²(A+120°)+cos²(A-120°)=3\2
Answers
Answered by
2
Step-by-step explanation:
that-cos²A+cos²(A+120°)+cos²(A-120°)
use formula
cosA+cos(A+120°)+cos(A-120°)
= Cos3A/4
Similar questions