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Stupid proof

  • Thread starter XodoX
  • Start date
  • #1
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Homework Statement


How do I show that the additive inverse, or negative, of an even number is an even number ( direct proof) ?


Homework Equations





The Attempt at a Solution



I have no idea. Anybody?
 

Answers and Replies

  • #2
hunt_mat
Homework Helper
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Really? Let [tex]a=2n[/tex] be an even number then the additive inverse [tex]b[/tex] is defined by [tex]a+b=0[/tex], so [tex]b=-a=-2n[/tex], and so...
 
  • #3
tiny-tim
Science Advisor
Homework Helper
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alternatively, start "an even number is a + a, so …" :wink:
 
  • #4
203
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Thanks! Makes sense now.
 

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