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sqrt question
04-26-2017, 03:08 AM
Post: #21
RE: sqrt question
(04-24-2017 09:36 PM)David Hayden Wrote:  
(04-09-2017 03:59 AM)Claudio L. Wrote:  sqrt(1) = 1
sqrt( (-1)*(-1) ) = sqrt(-1)*sqrt(-1) = i*i = -1
Isn't it:
sqrt(1) = 1 or -1.
sqrt( (-1)*(-1) ) = sqrt(-1)*sqrt(-1) = (+/-i)*(+/-i) = -1 or 1

The fact that we usually mean "the positive answer" when we say "sqrt(x)" doesn't negate the fact that there is also a negative answer.

You started reading the thread from the bottom up :-)
That post was intended as proof that even when selecting always the positive root as "the one true answer", it is possible to arrive to the other root by using trivial algebraic manipulations.
Otherwise, I agree with you and Han that both answers are correct and valid, one is not better than the other.
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Messages In This Thread
sqrt question - KeithB - 04-06-2017, 03:25 PM
RE: sqrt question - pier4r - 04-06-2017, 04:01 PM
RE: sqrt question - Namir - 04-06-2017, 04:02 PM
RE: sqrt question - KeithB - 04-06-2017, 04:51 PM
RE: sqrt question - Han - 04-06-2017, 05:46 PM
RE: sqrt question - pier4r - 04-06-2017, 05:15 PM
RE: sqrt question - KeithB - 04-06-2017, 06:03 PM
RE: sqrt question - Han - 04-06-2017, 06:18 PM
RE: sqrt question - Claudio L. - 04-07-2017, 01:23 PM
RE: sqrt question - Han - 04-07-2017, 04:48 PM
RE: sqrt question - Claudio L. - 04-07-2017, 09:15 PM
RE: sqrt question - Han - 04-07-2017, 10:54 PM
RE: sqrt question - Claudio L. - 04-09-2017, 03:59 AM
RE: sqrt question - David Hayden - 04-24-2017, 09:36 PM
RE: sqrt question - Claudio L. - 04-26-2017 03:08 AM
RE: sqrt question - Han - 04-28-2017, 06:09 PM
RE: sqrt question - nsg - 04-07-2017, 11:34 PM
RE: sqrt question - Vtile - 04-09-2017, 10:41 AM
RE: sqrt question - nsg - 04-09-2017, 05:26 PM
RE: sqrt question - Vtile - 04-09-2017, 11:07 PM
RE: sqrt question - nsg - 04-10-2017, 01:44 AM
RE: sqrt question - Vtile - 04-25-2017, 11:38 PM



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