11. Jika (fog) (x) = 4x²+2x+1 dan g(x) = 2x-1 maka f(x) adalah 10. Jika (fog)(x) = x² - 4x + 3 dan f(x) = x - 2 maka g(x) adalah

10. (fog)(x) = x^2 -4x +3
f(x) = x -2
ditanya : g(x) ?
jawab :
f(g(x)) = x^2 -4x + 3
g(x) -2 = x^2 -4x +3
g(x) = x^2 -4x + 5

11. (fog)(x) = 4x^2 + 2x +1
g(x) = 2x -1
ditanya : f(x) ?
jawab :
f(g(x)) = 4x^2 + 2x + 1
f(2x -1) = 4x^2 + 2x +1
misal
a = 2x -1
x = (a+1)/2
f(a) = 4((a+1)/2)^2 + 2((a+1)/2) + 1
f(a) = 4((a^2 +2a +1)/4) + a+1 +1
f(a) = a^2 +2a +1 + a +2
f(a) = a^2 + 3a + 3
f(x) = x^2 + 3x + 3

semoga bermamfaat ;;)