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Math Help - How to take limits of inverse functions!

  1. #1
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    How to take limits of inverse functions!

    ]How would you solve

    lim as x -> infinity f-1( x2 + 2 x + 1)

    ?

    Thanks!
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  2. #2
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    Re: How to take limits of inverse functions!

    Why not just find f^{-1} (x^2+2x+1) ?
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    Re: How to take limits of inverse functions!

    f(x) = x^2 +2x + 1 = (x+1)^2

    restricting the domain of f(x) to x > -1

    f^{-1}(x) = \sqrt{x} - 1

    the inverse is unbounded as x \to \infty


    I'm hoping you don't have confusion between inverse and reciprocal functions.
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  4. #4
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    Re: How to take limits of inverse functions!

    What you wrote was \lim_{x\to\infty} f^{-1}(x^2+ 2x+ 1) which we cannot help you with because you did not tell us what "f" is. Skeeter assumed you meant that f(x)= x^2+ 2x+ 1 and that you want to find \lim_{x\to\infty} f^{-1}(x). Is that correct?
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  5. #5
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    Re: How to take limits of inverse functions!

    Quote Originally Posted by HallsofIvy View Post
    What you wrote was \lim_{x\to\infty} f^{-1}(x^2+ 2x+ 1) which we cannot help you with because you did not tell us what "f" is. Skeeter assumed you meant that f(x)= x^2+ 2x+ 1 and that you want to find \lim_{x\to\infty} f^{-1}(x). Is that correct?
    that is another reason for my final statement ...
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  6. #6
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    Re: How to take limits of inverse functions!

    I'm interested to know why this Algebra/Pre Calculus question was posted in Statistics...
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    Re: How to take limits of inverse functions!

    Quote Originally Posted by Prove It View Post
    I'm interested to know why this Algebra/Pre Calculus question was posted in Statistics...
    not like it matters anymore ... the new owner/moderator hasn't been around for awhile. just note how many problems have been posted in the lobby.
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