Help with a ProofDate: 6 Apr 1995 14:27:55 -0400 From: Loic Dachary Subject: Proof I'm trying to figure out how to prove that a is less than b implies that a * a is less than b * b is true in R+ I'm not having any troubles with a is less than b, then a * a is less than b * b, but the opposite is beyond my capabilities. Can you help ? Thanks in advance, Loic Date: 7 Apr 1995 10:58:03 -0400 From: Dr. Sydney Subject: Re: Proof Hello, Loic! You asked a great question! Now, I'm not sure how rigorous you want to be with this, so if you want more rigor, just write back, and we'll be happy to help out. Let's assume that neither a nor b is 0 (you can address the case where a is 0 in a special case....write back if you aren't sure how to do that). Then, we can divide both sides by a*a right? (If you want a rigorous proof of this, let us know!) So, then you have the inequality : 1 is less than (b/a)^2 How does this help? Try and work with this, and see if you can come up with a proof! If this doesn't seem to be going anywhere and you want a little more help, or you want to try a different tack on the problem, just write us back! --Sydney, "dr. Math" |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994- The Math Forum at NCTM. All rights reserved.
http://mathforum.org/dr.math/