Diketahui (gof) (x) =2x²-4x-5 dan f(x) =x²+4x-2 tentukan a. G(x) b. (Fog) (13)

Jawaban:

(g○f)(x) = 2x^2 – 4x – 5

f(x) = x^2 – 2x + 10

a]

(g○f)(x) = g(f(x))

2x^2 – 4x – 5 = g(x^2 – 2x + 10)

(2x^2 – 4x + 20) – 25 = g(x^2 – 2x + 10)

2(x^2 – 2x + 10) – 25 = g(x^2 – 2x + 10)

g(x) = 2x – 25

b]

(f○g)(x) = f(g(x))

(f○g)(x) = f(2x – 25)

(f○g)(x) = (2x – 25)^2 – 2(2x – 25) + 10

(f○g)(x) = 4x^2 – 100x + 625 – 4x + 50 + 10

(f○g)(x) = 4x^2 – 104x + 685

(f○g)(13) = 4(13^2) – 104(13) + 685

(f○g)(13) = 4(169) – 104(13) + 685

(f○g)(13) = 676 – 1352 + 685

(f○g)(13) = 9

Penjelasan dengan langkah-langkah:

maaf kalau salah yha hehehe