Question

Prove that sin6A+cos6A = 1-3(sinA.cosA)2

Answer 1

sin(x) = cos(x-π/2) = -sin(x-π) = -cos(x+π/2) = sin(x+2π) csc(x) = sec(x-π/2) = -csc(x-π) = -sec(x+π/2) = csc(x+2π) tan(x) = -cot(x±π/2) = tan(x+π) tan(x+π/4) = (1+tan(x))/(1-tan(x))