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Math Help - inequality symbol reverse with logs question

  1. #1
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    inequality symbol reverse with logs question

    Hello

    I have an inequality where I have this equation:

    0.79^n < 0.1

    I assumed that if I take logs of both sides the result would be:

    n log 0.79 < log 0.1

    n < log 0.1 / log 0.79

    n < 9.768

    But actually result should be n > 9.768

    Why is the inequality symbol reversed in this situation?

    Angus
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  2. #2
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    e^(i*pi)'s Avatar
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    As \log(0.79) < 0 you have to reverse the direction of the inequality when dividing by negative numbers
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