Matematika

Pertanyaan

½log (x²-3) -½logx = -1

2 Jawaban

  • Logaritma , X

    ^½ log (x²-3) - ^½ log x = -1
    ^½ log ((x²-3)/x) = -1
    (x² - 3) /x = (½)^(-1)
    (x²-3) /x = 2
    x² - 3 = 2x
    x² - 2x - 3 = 0
    (x - 3)(x + 1) = 0
    x = 3
    x = -1

    -1 tidak terpakai krn numerus logaritma tidak blh negatif

    jawab : x = 3
  • log(1/2) (x^2 - 3) - log(1/2) (x) = -1
    log (1/2) (x^2 - 3) = log (1/2) (x) - 1
    log (1/2) (x^2 - 3) = log (1/2) (x) - log(1/2) 1/2
    log (1/2) (x^2 - 3) = log (1/2) (x ÷ 1/2)
    log (1/2) (x^2 - 3) = log (1/2) 2x
    x^2 - 3 = 2x
    x^2 - 2x - 3 = 0
    (x - 3)(x + 1) = 0

    x1 - 3 = 0
    x1 = 3

    x2 + 1 = 0
    x2 = -1 (tidak memenuhi)

    HP : {3}

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