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Math Help - logs

  1. #1
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    logs



    I did log_{2}(-1)1/9=log_2x^2
    (-1/9)=x^2
    ? cant take root of a negative and even If I did I get the wrong answer.
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  2. #2
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    Quote Originally Posted by brentwoodbc View Post


    I did log_{2}(-1)1/9=log_2x^2
    (-1/9)=x^2
    ? cant take root of a negative and even If I did I get the wrong answer.
    Using change of base you can write
    log(1/9)/log(1/2) = 2logx/log2.
    1/2*log(1/9)/-log(2) = log x/log2
    -log(1/3) = log x
    log3 = log x
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  3. #3
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    \log_{\frac{1}{2}}{\frac{1}{9}} = -\log_2{\frac{1}{9}} = \log_2{9}
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  4. #4
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    I thought my way should work, so ya the answer is +3 but I thought it could only be+ I guess because a negative number squared is a positive
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