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March 20th, 2013, 02:47 PM  #1 
Newbie Joined: Mar 2013 Posts: 1 Thanks: 0  Discrete math direct proof question
I have a question on my homework that I have no idea how to start. If someone could show me the steps for this problem so I can see how it is done that would be awesome! Thanks #1.) Prove using a direct proof that for every rational number x, if x ? 0, then 1/x is rational 
March 20th, 2013, 06:20 PM  #2 
Math Team Joined: Sep 2007 Posts: 2,409 Thanks: 6  Re: Discrete math direct proof question
"If x is rational, the what ?". What is the definition of "rational number"?

March 21st, 2013, 12:23 PM  #3 
Global Moderator Joined: May 2007 Posts: 6,607 Thanks: 616  Re: Discrete math direct proof question
If x is rational, then x = m/n, where m and n are integers. What can you say about 1/x?


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