Simple inequality problem

Maths and statistics discussion, revision, exam and homework help.

Announcements Posted on
Ask me ANYTHING - Andrew O'Neill - Buzzcocks comedian, amateur occultist, vegan... 22-05-2013
IMPORTANT: You must wait until midnight (morning exams)/4.30AM (afternoon exams) to discuss Edexcel exams and until 1pm/6pm the following day for STEP and IB exams. Please read before posting, including for rules for practical and oral exams. 28-04-2013
Sign in to Reply
  1. Julii92's Avatar
    • Adored and Respected Member
    • Posts: 443
    Simple inequality problem
    This is a simple problem but I can't quite get my head around it. I'm given the inequality n2-101n+2000<0 and I have to find the largest possible value of n. The answer is 73 but I don't know how to get it.

    When I picture a quadratic the x-variable (in this case, n) goes on forever in both the positive and negative directions, so the concept of a maximum value for it is confusing me. If it were to ask for the maximum value of the function, I'd have more of an idea of what to do.
  2. Arva's Avatar
    • Vengeful, Imperial Overlord of The Student Room
    • Posts: 4,789
    Re: Simple inequality problem
    Just whack it into the quadratic formula.
  3. notnek's Avatar
    • TSR Demigod
    • Location: Bangkok, Thailand
    Re: Simple inequality problem
    Are you sure the question doesn't ask to find the largest integer value of n?
  4. Lord of the Flies's Avatar
    • The foul fiend Flibbertigibbet
    • Location: Paris, France
    Re: Simple inequality problem
    (Original post by Julii92)
    This is a simple problem but I can't quite get my head around it. I'm given the inequality n2-101n+2000<0 and I have to find the largest possible value of n. The answer is 73 but I don't know how to get it.

    When I picture a quadratic the x-variable (in this case, n) goes on forever in both the positive and negative directions, so the concept of a maximum value for it is confusing me. If it were to ask for the maximum value of the function, I'd have more of an idea of what to do.
    I can't see any pretty way of doing this. Solve n^2-101n+2000=0, then take \lfloor n_0\rfloor where n_0 is the largest positive solution.
    Last edited by Lord of the Flies; 11-06-2012 at 12:48.
  5. Julii92's Avatar
    • Adored and Respected Member
    • Posts: 443
    Re: Simple inequality problem
    Got it - thanks.
Sign in to Reply
Share this discussion:  
Article updates
Moderators

We have a brilliant team of more than 60 volunteers looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Reputation gems:
The Reputation gems seen here indicate how well reputed the user is, red gem indicate negative reputation and green indicates a good rep.
Post rating score:
These scores show if a post has been positively or negatively rated by our members.