Matematika

Pertanyaan

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

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

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