jika ( f ° g ) (x) = 4x² + 2x dan g(x) = 2x - 1, maka f (x) adalah...... a.x²+3x +1 b.x²+3x+2 c.x²+3x+3 d.x²+3x+4 e.x²+3x+5 tolong jawabnya pakai caranya......

(f ○ g)(x) = 4x^2 + 2x
f(g(x)) = 4x^2 + 2x
f( 2x - 1) = 4x^2 + 2x >> 2x - 1 = t
f (x) = 4(t + 1/ 2)^2 + 2(t + 1/ 2) > x = t + 1/ 2
f(x) = 4( t^2 + 2t + 2 / 4) + (t + 1)
f(x) = t^2 + 3t + 3
f(x) = x^2 + 3x + 3 ( c )