F(x)=3x-1 dan fungsi komposisi (gof)(x)=18x²-12x+5 Rumus fungsi g(x)=? Dimohon bantuannya

Mapel : Matematika

Kelas : 10

Bab : Fungsi komposisi
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f(x) = 3x - 1

(g o f) (x) = 18x² - 12x + 5

Ditanya → Nilai fungsi g(x)

Penyelesaian :
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Misalkan :

3x - 1 = y

3x = y + 1

x = y + 1/3

Maka,

(g o f) (x) = 18x² - 12x + 5

g(f(x)) = 18x² - 12x + 5

g(x) = 18[(x + 1)/3)²] - 12(x + 1)/3 + 5

g(x) = 18[(x² + 2x + 1)/9)] - 4x - 4 + 5

g(x) = 2x² + 4x + 2 - 4x - 4 + 5

g(x) = 2x² + 3 ✔