F(x)=x²+6x+4 dan gof(x)=x+3
(gof)(x) = x + 3
g(f(x)) = x + 3
g(x² + 6x + 4) = x + 3
Misal y = x² + 6x + 4 maka
y = x² + 6x + 9 – 5
y = (x + 3)² – 5
y + 5 = (x + 3)²
±√(y + 5) = x + 3
-3 ± √(y + 5) = x
g(y) = (-3 ± √(y + 5) + 3
g(y) = ± √(y + 5)
g(x) = ± √(x + 5)