Matematika

Pertanyaan

Suatu suku banyak f(x) dibagi x-1 siaanya 6 dan dibagi x+3 sisanya -2. Bila fx dibagi x2+2x-3

1 Jawaban

  • f(1) = 6
    f(-3) = -2

    misal s(x) = ax + b

    f(x) = (x^2 + 2x - 3)×H(x) + S(x)
    f(x) = (x - 1)(x + 3)×H(x) + ax + b
    f(1) = (1-1)(1+3)×H(1) + a×1 + b
    f(1) = 0(4)×H(1) + a + b
    6 = 0 + a + b
    a + b = 6 ...... (1)

    f(-3) = (-3-1)(-3+3)×H(-3) + a×(-3) + b
    f(-3) = (-4)(0)×H(-3) + (-3a) + b
    -2 = 0 - 3a + b
    3a - b = 2 .......(2)

    dari (1) dan (2)

    a + b = 6
    3a - b = 2
    ________ +
    4a = 8
    a = 2


    b = 6 - a
    b = 6 - 2
    b = 4

    s(x) = 2x + 4

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