Question

8. Prove that....
cos(a + B + y) + cos(a - B +y)+cos (a + B - y)+cos(-a + B + y) = 4cos a cos B cos y

Note- a = Alpha, B = Beta , Y = gama

I will mark as brainliest to whom, who give me step by step Explaination​

Answer 1

Answer:

ጉግል ውስጥ ይፈልጉ እና ሌሎችን አይስሩ