Question

can any person give me answer
please

Answer 1

COS2A =2COS²X-1
=BY OPEN IT
LIKE 1=SIN²X+COS²X
THE PUT THE VALUE OF 1
=2COS²X-SIN²X-COS²X
=COS²X-SIN²X

Answer 2

by the trigonometric identities i.e

cos(a+b) =cos (a) *cos(b) - sin(a) *sin(b)

cos(2a) = cos(a+a)= cos (a) *cos(a) - sin (a) *sin(a) = cos²(a) - sin²(a)

hope it helps and would u mark me brainiest