Diketahui f(x)= x²-4x+5 dan g(x)=5x-7 tentukan a. (f o g) (-2) b. (g o f)(3) c.[tex] f^{-1} [/tex] (1) d. [tex] g^{-1} [/tex] (2)
Matematika
ryuliet91
Pertanyaan
Diketahui f(x)= x²-4x+5 dan g(x)=5x-7 tentukan
a. (f o g) (-2)
b. (g o f)(3)
c.[tex] f^{-1} [/tex] (1)
d. [tex] g^{-1} [/tex] (2)
a. (f o g) (-2)
b. (g o f)(3)
c.[tex] f^{-1} [/tex] (1)
d. [tex] g^{-1} [/tex] (2)
2 Jawaban
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1. Jawaban xkuadratz
f(x)= x²-4x+5 dan g(x)=5x-7
a. g(2) = 5.(2)-7 = 3
(fog)(2) = f(g(2)) = 3²-4(3)+5 = 9 - 12 + 5 = 2
b. f(3) = 3²-4(3)+5 = 9 - 12 + 5 = 2
gof(3) = g(f(3)) = 5(2)-7 = 10-7 = 3 -
2. Jawaban yoesamudra
a)g(-2) = 5(-2) - 7
= -10 - 7
= -17
fog(-2) = -17² - 4(-17) + 5
= 289 + 68 + 5
= 362
b)
f(3) = 3² - 4(3) + 5
= 9 - 12 + 5
= 2
gof(3) = 5(2) - 7
= 10 - 7
= 3
c)
[tex] f^{-1} [/tex] = -(x² - 4x + 5)
= -x² + 4x - 5
[tex] f^{-1} (1)[/tex] = -1² - 4(1) + 5
= 2
[tex]g^{-1} [/tex] = -(5x + 7)
= -5x - 7
[tex]g^{-1} [/tex](2) = -5(2) - 7
= -17