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Topic: re: #32
Replies: 23   Last Post: Jun 18, 2010 5:18 AM

 Messages: [ Previous | Next ]
 precopio@nycap.rr.com Posts: 102 Registered: 8/26/09
Re: #32
Posted: Jun 16, 2010 4:38 PM
 att1.html (2.8 K)

hmmm.. actually what if x = -2? Then sq rt of (-2)cubed = 2i sq rt 2. But if x = -2 and you are doing the sq rt of (-2) squared that would still just be 2. I think. In which case you are right. I think. I'm rethinking all my math knowledge now!!
----- Original Message -----
From: TKENYON@crcs.wnyric.org
To: nyshsmath@mathforum.org
Sent: Wednesday, June 16, 2010 3:45 PM
Subject: re: #32

Which is why is should be absolute value of x, because while you assume the positive square root (principal root), you don't know that x is positive - it was never indicated that the domain was positive values of x.
(I'm not sure if we're in agreement, or doing two different things.)

when solving an equation x squared = 9, then yes the answer is + and - 3, but when it is written as a square root, you assume the positive square root.

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