Question

if 2sinA=2-cosA,find sinA

Answer 1

Let SinA = x.So cosA = (1-x2)1/2.Hence the eqn, 2x = 2 - (1-x2)1/2.Or (1-x2)1/2 = 2 - 2xSquaring, we have, 4+4x2-8x = 1-x2.or 5x2 - 8x + 3 = 0.(5x-3)(x-1) = 0.So x = 1 or x = 3/5So SinA = 1 or 3/5.