Question

(a cos 0 + b sin 0)^2 + (a sin 0 - b cos 0)2 = a^2 + b^2​

Answer 1

Answer:

LHS = (a cos 0 + b sino)^2 + ( a sin 0 - b cos 0)^2

= a^2 cos^2 0+ b^2 sin^2 0 +2 a.b. sin0. cos 0 + a^2 sin^20 + a^2 cos^2 0 - 2.a.b sin 0. cos 0

= (a^2 + b^2)( cos^2 0+ sin^2 0) = a^2 + b^2 = RHS