Question

1. Bila f(x) = 4x + 2 dan (f o g)(x) = 12x - 2 maka g(x) =....
2. Bila f(x) = 2x^2 - 2 dan g(x) = x + 2 maka (f o g)(x) =....
3. Jika f(x) = x^2 dan g(x) = 3x + 1 maka f(g(2)) adalah...

Answer 1

1. f(x) = 4x+2
(f o g)(x) = 12x -2
f(g(x)) = 12x-2
f.g(x) = 12x-2
4.g(x)+2 = 12x-2
4.g(x) = 12x-2-2
4.g(x) = 12x-4
g(x) = 1/4(12x-4)
g(x) = 3x-1

2. f(x) = 2x^2-2
g(x) = x+2

(f o g)(x) = f(x) o g(x)
= 2x^2-2 o x+2
= 2(x+2)^2-2
= 2(x^2+4x+4)-2
= 2x^2+8x+8-2
= 2x^2+8x+6

3. f(x) = x^2
g(x) = 3x+1

f(g(x)) = f(x) o g(x)
= x^2 o 3x+1
= (3x+1)^2
= 9x^2+6x+1
f(g(2)) = 9(2)^2+6(2)+1
= 9(4)+12+1
= 36+ 13
= 49

maaf ya kalo salah