Results 1 to 2 of 2

Math Help - Limit problem that stumped me

  1. #1
    TWN
    TWN is offline
    Junior Member
    Joined
    May 2010
    Posts
    35

    Limit problem that stumped me

    Might be overlooking something simple, but I'm having trouble figuring this out:

    As x approaches infinity, what is the limit of

    ( -5x^7 + 5x^6 - 3x^5 - 4x^4 ) / ( -7x^4 + x^3 )

    I narrowed it down to this:

    ( -5x^3 + 5x^2 - 3x - 4 ) / -7

    Then plugged-in infinity where x is...

    ( -∞ + ∞ - ∞ - 4 ) / -7

    Then I don't know what to do because I can't subtract infinity from infinity...

    Someone please explain in detail how to solve this and other problems like it. Thanks in advance!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454

    Re: Limit problem that stumped me

    Quote Originally Posted by TWN View Post
    Might be overlooking something simple, but I'm having trouble figuring this out:

    As x approaches infinity, what is the limit of

    ( -5x^7 + 5x^6 - 3x^5 - 4x^4 ) / ( -7x^4 + x^3 )

    I narrowed it down to this:

    ( -5x^3 + 5x^2 - 3x - 4 ) / -7

    Then plugged-in infinity where x is...

    ( -∞ + ∞ - ∞ - 4 ) / -7

    Then I don't know what to do because I can't subtract infinity from infinity...

    Someone please explain in detail how to solve this and other problems like it. Thanks in advance!
    degree numerator > degree of the denominator, the rational function will either increase or decrease w/o bound.

    if you did not learn all this in precalculus (and you should have), then check this out ...

    Rational Functions

    ... scroll down to Rational function end behaviors are all about ratios, but I recommend you look over the entire article.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Strange Problem has me stumped
    Posted in the Algebra Forum
    Replies: 1
    Last Post: September 23rd 2010, 02:49 AM
  2. Integration Problem Has Me Stumped
    Posted in the Calculus Forum
    Replies: 2
    Last Post: July 4th 2010, 12:53 AM
  3. Completely stumped on this problem!
    Posted in the Algebra Forum
    Replies: 4
    Last Post: October 13th 2009, 04:55 PM
  4. A limit that finally stumped me!
    Posted in the Calculus Forum
    Replies: 9
    Last Post: September 16th 2008, 04:13 PM
  5. Stumped on a math problem
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 19th 2008, 03:08 PM

Search Tags


/mathhelpforum @mathhelpforum