jika f(x) = 2x + 3 dan g(x) = x^2 . tentukan nilai ( f + g )^2 =

jawab

(f + g)² (x) =  ( 2x + 3 + x²)² = (2x + 3 + x²)(2x + 3 + x²)

= 2x(2x + 3 + x²) + 3(2x + 3 + x²) + x²(2x + 3 + x²)
= 4x²+ 6x + 2x³ + 6x +9 + 3x² + 2x³ + 3x²  + x⁴
= x⁴ + 4x³ + 10x² + 12x + 9