Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: syhprum on 14/09/2007 17:15:13
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whenever I get to test a pocket scientific calculator I ask it to evaluate the cube root of -1, some manage OK but most give up the ghost why?
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Probably because most are not programmed to handle imaginary numbers.
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That I could understand but the cube root of -1 is -1 not imaginary
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That I could understand but the cube root of -1 is -1 not imaginary
This is true, but did the programmer who programmed the calculator understand that?
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That I could understand but the cube root of -1 is -1 not imaginary
Sorry, I mistook cube for square [:I]
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That I could understand but the cube root of -1 is -1 not imaginary
This is true, but did the programmer who programmed the calculator understand that?
[;D]
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ONE of the cube roots of -1 is REAL
There are two others!! They are complex.
There's plenty of links on google for this.
Cubic equations have three roots and they are not necessarily real.
A good calculator would be smart enough to point this out to you.
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I have downloaded two software calculators that are not freeware and they both give the answer as -1 but the calculator that comes with Windows XP cannot cope with it.
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ONE of the cube roots of -1 is REAL
There are two others!! They are complex.
There's plenty of links on google for this.
Cubic equations have three roots and they are not necessarily real.
A good calculator would be smart enough to point this out to you.
Ok, but a very good calculator would be smart enough to give all the three values...
If it's limited to real values only, then it should give -1 as result. You cannot say that, actually, it can't answer because there are more than one solution: why, then, 21/2 gives 1,414213562 only and not -1,414213562 too?
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A really smart machine would have to give some extra comments about validity of results and, as you say, lists of alternative answers.
Wolfram's Mathematica is one bit of software which works in the right direction. It's annoyingly clever at all the Maths I learned at School and later.
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My spreadsheet programs just give errors [:(]
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http://mathworld.wolfram.com/
This is a good start point to see what Wolfram's Mathematica is all about