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Math Help - Logarithmic Equation

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    Exclamation Logarithmic Equation

    I don't completely understand how logarithmic equations work...please help!

    Find the domain of the function:

    f(x)=log(sub2)(36-x(squared))

    f(x)=log(sub10)(x+6/x-5)
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  2. #2
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    Quote Originally Posted by kanej316 View Post
    I don't completely understand how logarithmic equations work...please help!

    Find the domain of the function:

    f(x)=log(sub2)(36-x(squared))

    f(x)=log(sub10)(x+6/x-5)
    The domain of a log function must always be greater than 0. This means you can solve what is being taken to 0 and find values for which the domain cannot be:

    Using your first example:

    36-x^2 = 0

    This is the difference of two squares with a = 6 and b =x

    (6-x)(6+x) = 0

    x = \pm6

    Therefore values between -6 and 6 is the domain, to put it another way:

    -6< x < 6 or |x| < 6
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