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AcademicGround >> Imaginary numbers. Explain them here.


9/17/09 2:49 AM
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amorphous
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Granted I am only at a Calc 1 level so I haven't dealt with them too much...but what are they? You can give a "no shit sherlock" answer of "well duh it's just a number times the square root of negative one!!1" but they just seem so strange to me.

I understand they have practical use it just seems like they don't really exist. I don't know how to describe it they are just weird.
9/27/09 1:24 AM
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tmr
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I think you just smoked yourself retarded!
9/27/09 10:27 PM
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amorphous
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LOL
9/28/09 3:42 PM
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tmr
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amorphous - LOL

 wish i could be of more use ;)
11/5/09 7:56 PM
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big fatso
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Read An Imaginary Tale: The story of (square root of) -1 if you want to learn the complicated story behind its use and realness. They are no more imaginary than negative numbers or irrational ones.
11/10/09 3:29 PM
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P.V.Jena
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 Think a bit about why non-complex numbers seem more real to you.

4/6/10 10:53 AM
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signaljammer
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Edited: 04/06/10 10:53 AM
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sqrt of negative one is an incomplete definition of i..

i is actually a four way commutator, like -1 is a two way commutator.

e.g. -1^x = 1 if x is even or = -1 if x is odd.

now,

i^1 = i (duh), i^2 = -1, BUT ALSO: i^3 = -i, and i^4 = 1

and then the cycle repeats, going through four values.

now, complex numbers are a pair of reals, one of which is multiplied by i. This means instead of a number line, you now have a plane, with two axis, one real axis, and one imaginary axis.

(a, b*i) is now your number.

the rules are largely algebraic, but you should look at a formal text. absolute value is different now, it is the distance to the origin. also, you can't really order numbers anymore directly. (i.e. < or > lose meaning)

umm, yeah.
7/1/10 3:48 PM
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MMA_KNOWLEDGE
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We used them in my electrical engineering class and they had a practical purpose but I have forgotten it at this point.
7/12/10 7:58 PM
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Entreri
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fuck man, you just need to use your imagination

it ain't rocket science

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