Question

cos square teta+cos square (2π\3+ teta)+cos square ( 2π\3- teta)= 3\2​

Answer 1

Answer:

hope it helps you. .....

Answer 2

Answer:

We can use the sum and difference formulas for cosine to expand.

(cosα)2+(cos(2π3)cosα−sin(2π3)sinα)2+(cos(2π3)cosα+sin(2π3)sinα)2=32

(cosα)2+(−12cosα−(√32sinα))2+(−12cosα+√32sinα)2=32

(cosα)2+14cos2α+34sin2α+√34cosαsinα+14cos2α+