Matematika

Pertanyaan

mohon bantuan nya, mohoon banget, beberapa nomer juga gpp, soalnya tugas nya bsk di kumpulkan....

terimakasih....
mohon bantuan nya, mohoon banget, beberapa nomer juga gpp, soalnya tugas nya bsk di kumpulkan.... terimakasih....

1 Jawaban

  • 1) f(x) = 4 / 2(3-x) = 2 / (3-x)
    y = 2 / (3-x)
    y(3-x) = 2
    3y - xy = 2
    3y - 2 = xy
    x = (3y-2)/y
    → invers f(x) = (3x-2)/x
    invers f(4) = (3.4-2)/4
    = (12-2)/4 = 10/4 = 5/2

    2) f(x) = 4x + 12
    y = 4x + 12
    y - 12 = 4x
    x = ¼(y-12)
    → invers f(x) = ¼(x-12)

    3) f(x) = 2x / (2x-2)
    y = 2x / (2x-2)
    y(2x-2) = 2x
    2xy - 2y = 2x
    2xy - 2x = 2y
    x(2y-2) = 2y
    x = 2y / (2y-2)
    → invers f(x) = 2x / (2x-2)

    4) f(x) = 4x
    g(x) = 6 - 10x
    (g•f)(x) = 6 - 10(4x) = 6 - 40x
    y = 6 - 40x
    40x = 6 - y
    x = (6-y)/40
    → invers (g•f)(x) = (6-x)/40

    5) f^-1(x) = 6x + 3
    g^-1(x) = x²
    (f•g)^-1(x)
    = (g^-1 • f^-1)(x)
    = (6x + 3)² = 36x² + 36x + 9

    6) g(x) = 6-10x
    (g•f)(x) = 6-20x
    6 - 10(f(x)) = 6 - 20x
    6 - 6 + 20x = 10 (f(x))
    20x = 10 (f(x))
    f(x) = 20x/10 = 2x

    7) f(x) = 4x²-6
    f(f(x)) = f(4x²-6)
    = 4(4x²-6)²-6
    = 4(16x⁴-48x²+36)-6
    = 64x⁴-192x²+144-6
    = 64x⁴ - 192x² + 138

    8) f(x) = 4x + 2x = 6x
    g(x) = 2x²+2
    h(x) = 4x
    (h•g•f)(x)
    = h(g(6x))
    = h(2(6x)²+2)
    = h(12x²+2)
    = 4(12x²+2) = 48x²+8

    9) f(x) = 4x
    (f•g)(x) = -½x + 1
    4 g(x) = -½x + 1
    g(x) = ¼(-½x+1)
    g(x) = -⅛x + ¼

    10) f(x) = 8x
    g(x) = 2 + 2x²
    h(x) = 2x-4
    (f•g•h)(x)
    = f(g(2x-4))
    = f(2 + (2+2x)²)
    = 8(2 + (2+2x)²)
    (f•g•h)(2)
    = 8(2+ (2+2.2)²)
    = 8 (2 + 6²)
    = 8 (38) = 304