Matematika

Pertanyaan

Jika f(x) = 2x-3 dan (f o g) (x) = 5-2x/x+3 ,maka g-¹(2) =...

1 Jawaban

  • langsung aja yy

    (fog)(x) = f{g(x)}

    5 - 2x / x + 3= 2g(x) - 3

    5 - 2x = 2x.g(x) - 3x + 6g(x) - 9

    5 - 2x + 3x + 9 = g(x) (2x + 6)

    x + 14 = g(x) (2x + 6)

    (x + 14) / (2x + 6) = g(x)

    maka

    gog`¹(x) = x
    g{g`¹(x)} = x
    g`¹(x) + 14 / 2g`¹(x) + 6 = x
    g`¹(x) + 14 = 2x.g`¹(x) + 6x
    g`¹(x) - 2x.g`¹(x) = 6x - 14
    g`¹(x) (1 - 2x) = 6x - 14
    g`¹(x) = 6x - 14 / 1 - 2x

    maka
    g`¹(2) = 6(2) - 14 / 1 - 2(2)
    g`¹(2) = 12 - 14 / 1 - 4
    g`¹(2) = -2 / -3
    g`¹(2) = ⅔

    semoga berguna +_+

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