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Math Help - Hi all ....

  1. #1
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    Hi all ....

    Hi
    In this question How I know 0,000001 = 10^-2
    Is there a way ? Is there a way by Calculator ?
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  2. #2
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    Quote Originally Posted by r-soy View Post
    Hi
    In this question How I know 0,000001 = 10^-2
    Is there a way ? Is there a way by Calculator ?
    this is wrong,..

     0,000001 = \frac{1}{100000} = 10^{-6} not 10^{-2}
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  3. #3
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    sorry i mean 0,0001 = 10^-2

    i can't undertand your way


    Is there another way ?
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  4. #4
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    Quote Originally Posted by r-soy View Post
    sorry i mean 0,0001 = 10^-2

    i can't undertand your way


    Is there another way ?
    0,0001 = 10^-2 is wrong too.
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  5. #5
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    hhh i am confused

    i mean 0,0001 = 100^-2

    see the image and see the solving
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  6. #6
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    Remember that \log_a{b}=c \Longleftrightarrow\ a^{c} = b, with \log_a{b}=c well defined.

    What it's written in yor exercise is just the aplication of the above.

    Thus, you know \log_b{0,0001}=-2 \Longleftrightarrow\ b^{-2}=0,0001, but also know 0,0001=10^{-4}=(10^{2})^{-2}, because a propertie of powers says (a^{b})^{c}=a^{bc} with (a^{b})^{c} well defined.

    Therefore, b=100
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  7. #7
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    Without logarithms, 0,0001 ("one ten thousandth") means 1/10000= 1/(10)(10)(10)(10)= 1/10^4= 10^(-4).

    0,01= 1/100= 1/(10^2)= 10^(-2).

    Easy way- count the number of "decimal places"= 0,0001 has four places so is 10^(-4), 0,01 has 2 places so is 10^(-2).
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