g(x) = x+3 dan (fog)(x) = 2x^2 + 7x + 20 maka f(x)=
Matematika
christianping
Pertanyaan
g(x) = x+3 dan (fog)(x) = 2x^2 + 7x + 20 maka f(x)=
1 Jawaban
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1. Jawaban Syahrudi
[tex] (fog)(x) = 2x^2 + 7x + 20 \\ f(g(x)) = 2x^2 + 7x + 20 \\ f(x + 3) = 2 {(x + 3)}^{2} - 5x + 2 \\f(x + 3) = 2 {(x + 3)}^{2} - 5(x + 3) + 17 \\ andai \: x + 3 = k \: maka \\ f(k) = 2 {k}^{2} - 5k + 17 \\ f(x) = 2 {x}^{2} - 5x + 17[/tex]