Question

Dik f(x)=2x^2+4x+5
g(x)=2x+2
tentukan fog(x) dan gof (x)

Answer 1

Gof(x) = g(f(x))
         = g(2x²+4x+5)
         = 2(2x²+4x+5)+2
         = 4x²+8x+10+2
         = 4x²+8x+12

Answer 2

(f o g)(x) = f(g(x))
= f(2x + 2)
= 2(2x + 2)² + 4(2x + 2) + 5
= 2(4x² + 8x + 4) + 8x + 13
= 8x² + 16x + 8 + 8x + 13
= 8x² + 24x + 21

(g o f)(x) = g(f(x))
= g(2x² + 4x + 5)
= 2(2x² + 4x + 5) + 2
= 4x² + 8x + 12