Question

prove that Cos ²x+Cos²(x+π/3) +Cos²(x-π/3)=3/2

Answer 1

Answer:

cos²x + cos²(x+π/3)+cos²(x-π/3)=3/2

cos²(x+(x+π/3)+(x-π/3)=3/2

π=180.. here .

cos²(x+(x+180/3) +(x-180/3) = 3/2

cos²(3x+90-90)= 3/2

so cos²(3x)= 90+90

cos²x=90+90/3

cos²x = 180/3

cos²x=60

cos60 = 3/2

hence we have proved....

Answer 2

hope it will help you......