Question

Cos 20°+ cos80°-√3 cos50°​

Answer 1

Answer:

Formula :

cos C + cos D = 2cos C+D/2 × cos C-D/2

Answer 2

Given; Cos 20°+ cos80°-√3 cos50°​

To Find; The result

Solution;

cosC+cosD=cos(C+D/2)*cos(C-D/2)

Cos 20°+ cos80°-√3 cos50°​

cos50*cos30 - √3 cos50

-√3 cos50/2

Hence the result is -√3 cos50/2