1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Proof in simple Algebra

  1. Mar 28, 2005 #1
    Hi,

    I need to prove that for every a > 1 and b > 1 the following holds:

    ab - a - b + 2 > 1

    Can someone please throw me some hints? :)

    Thanks,
    Chen
     
  2. jcsd
  3. Mar 28, 2005 #2
    It's equivalent to proving

    ab - a - b + 1 > 0
    <=>
    a(b - 1) - b + 1 > 0
    <=>
    -a(b - 1) + b - 1 < 0
    <=>
    (b - 1)(1 - a) < 0.
     
  4. Mar 28, 2005 #3
    Argh, I was close but didn't see that! Thanks. :-)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...
Similar Threads for Proof simple Algebra Date
Simple Harmonic Motion proof Feb 18, 2015
Simple Algebra Proof: Finding all elements of a Group, S. Oct 5, 2011
Simple pendulum proof Jan 7, 2008
Simple limit proof Oct 1, 2005
Simple Proof Sep 8, 2005