Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Limit as x approaches infinity and negative infinity?

For a problem like x+32/(x^2), how do I find the limit at infinity and negative infinity?

2 Answers

Relevance
  • 5 years ago
    Favorite Answer

    For infinity limits, you would divide every term by the highest degree term, so for this case x^2 is the highest degree term, so after dividing your function would be...

    1/x + 32/(x^2)

    Now just substitute in infinity into the function, and the answer should be zero.

    If you don`t get it, basically any number divided by infinity will always equal zero, since any number divided by zero equals infinity.

    You would also get the same answer for as the function approaches negative infinity.

  • 5 years ago

    limit as x approaches +infinity = 0

    limit as x approaches -infinity = 0

    The reasoning: Divide numerator and denominator by by x that is multiply by (1/x) / (1/x) since this is equal to one we don't "change" the equation at all, but we get the new fraction:

    (x/x + 32/x) / x^2 / x

    Simplify to get (1 + 32/x) / x

    We know that 1/x^a where a > 0 yields the value 0 as x approaches infinity, therefore we can say that 32/x = 0 as x approaches infinity, we now have 1 / x, and once again use this identity to see the limit approaches 0.

    The negative infinity evaluation is the same.

Still have questions? Get your answers by asking now.