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RonPurewal
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Re: Is SQRT( (x-5)^2 =5-x?

by RonPurewal Mon Sep 16, 2013 9:07 am

(D) What is the correct rephrase of "Is |x| = y?"

"Is x = y? and x ≥ 0? or Is -x = y? and x ≤ 0?"
OR
"Is x = y? and x > 0? OR Is -x = y? and x < 0?"

Thank you in advance


The second set is incomplete, because it leaves out the case x = y = 0. The first successfully captures that case.

You could also write them as "≥" and "<", respectively, or as "<" and "≤".
As long as you've captured the case x = y = 0 in at least one of your cases (i.e., as long as you have at least one of "≥" and "≤"), you're good.