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: Discrete Math Help

  1. Jan 28, 2005 #1
    Prove that for any vectors a and b, |a-b| is less than or equal to |a| + |b|

    I'm kind of lost, b/c i can't see a case where |a-b| would actually result in a value being less than |a| + |b|.

    I've tried doing a proof that is similar, and when I was taught, the definition of absolute value was used to prove it.
     
  2. jcsd
  3. Jan 28, 2005 #2
    |x|>|y| if and only if |x|^2 > |y|^2

    square both side and you will see the relationship
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook