jika g(x-1) = 4x²-8x+4 dan ( fog)(x) =8x²+3, maka nilai f (1) adalah

g(x - 1) = 4x^2 - 8x + 4
g(x - 1) = 4(x^2 - 2x + 1)
g(x - 1) = 4(x - 1)^2
g(x) = 4x^2

(f o g)(x) = 8x^2 + 3
f(g(x)) = 2 . 4x^2 + 3
f(4x^2) = 2 . 4x^2 + 3
f(x) = 2x + 3
f(1) = 2(1) + 3 = 5

x-1 = y
x = y+1
x = x+1

g(x) = 4(x+1)² - 8(x+1) + 4
= 4(x²+2x+1) - 8x - 8 + 4
= 4x² + 8x + 4 - 8x - 4
= 4x²

4x² = y
x² = y/4
x = √y/4
x = √x/4

f(x) = 8(√x/4)² + 3
= 8(x/4) + 3
= 8x/4+ 3
= 8x+12/4

f(1) = 8(1)+12 / 4
= 8+12 / 4
= 20/4
= 5