Question

if cos square theta + sin square theta equal to root 2 cos square theta show that cos square theta minus sin square theta equal to root 2 sin squared theta​

Answer 1

Step-by-step explanation:

cos2thetA+sin2theta=root 2cos2theta

to prove -cos2theta -sin2theta = root 2sin2theta

here,

or,cos2theta + sin2theta=root 2cos2theta

or, cos2theta=root 2cos2theta-sin2theta

again

now,

lhs=rhs

cos2theta-sin2theta =root 2 sin2theta

or,root2cos2theta-2sin2theta=root 2 sin2theta

or, 2