(properties of mulitiplication of inequalities) |
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[[Category:MA375Spring2009Walther]] | [[Category:MA375Spring2009Walther]] | ||
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+ | [[Category:MA375Spring2009Walther|inequality multiplication]] | ||
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+ | There is a property of inequalities that states: <br/> | ||
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+ | if c is some positive number and a < b, then ac < bc <br/> | ||
+ | if c is some negative number and a < b, then ac > bc <br/> | ||
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+ | From this property we can prove inequalities such as the following: | ||
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+ | If a<b and c<d, where a, b, c, and d are positive numbers then ac<bd must be true. |
Latest revision as of 05:44, 29 January 2009
Is there a formal way of saying a<b and c<d implies ac<bd, like a theorem from algebra or something? Just wondering because I used it for my inductive step.
I believe the way you wrote it should be fine for the proof.
There is a property of inequalities that states:
if c is some positive number and a < b, then ac < bc
if c is some negative number and a < b, then ac > bc
From this property we can prove inequalities such as the following:
If a<b and c<d, where a, b, c, and d are positive numbers then ac<bd must be true.