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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
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