serafins Posted November 2, 2005 Share Posted November 2, 2005 Let X = 0.99999... 10X = 9.99999... 10X - X = 9.99999... - 0.99999... 9X = 9 X = 1 :pinch: Link to comment Share on other sites More sharing options...
ninjamunky Posted November 2, 2005 Share Posted November 2, 2005 The last one is impossible... If you simplify by substituting in the given value for X it you get: 9 * 0.99999... = 9 which is not a true statement. Correct? Link to comment Share on other sites More sharing options...
Zip Posted November 2, 2005 Share Posted November 2, 2005 thats just a rounding error Link to comment Share on other sites More sharing options...
Mateus Posted November 2, 2005 Share Posted November 2, 2005 Wot r u smoking? 10 * 0.9999999999 = 9.999999999 9.999999999 - 0.9999999999 = 9.9999999980000000001 9 * 0.9999999999 = 8.9999999991 Errr?! Link to comment Share on other sites More sharing options...
Tungsten T Posted November 2, 2005 Share Posted November 2, 2005 9X is not 9 Link to comment Share on other sites More sharing options...
grimreaper Posted November 2, 2005 Share Posted November 2, 2005 Let X = 0.99999...10X = 9.99999... 10X - X = 9.99999... - 0.99999... 9X = 9 X = 1 :pinch: 586757333[/snapback] hmmm... weird Link to comment Share on other sites More sharing options...
styxie Posted November 2, 2005 Share Posted November 2, 2005 Not true, it all comes down to the last 9 in the numbers. Let's say X = 0.9999 (four 9's). 10X = 9.9990 (I'll take 4 decimals for convenience) 10X - X = 9.9990 - 0.9999 9X = 8.9991 So still X = 0.9999 Link to comment Share on other sites More sharing options...
khaos34 Posted November 2, 2005 Share Posted November 2, 2005 So basically, in step two, you did "Ten times an infinite sequence"... You can't just move the decimal. "1" just so happens to be the limit of that infinite sequence of nines, so ten times that wouldn't give you 9.9999999... it'll only give you 10x, since x represents that sequence. Using the result of 9.99999... is incorrect since you're actaully changing what "x" represents. Edit: ^ Long explanation relates to what Tungsten said already :D "9X is not 9" Link to comment Share on other sites More sharing options...
blik Posted November 2, 2005 Share Posted November 2, 2005 0.9 recurring IS equal to 1... There's nothing wrong with your proof either... Lord Method Man 1 Share Link to comment Share on other sites More sharing options...
khaos34 Posted November 2, 2005 Share Posted November 2, 2005 0.9 recurring IS equal to 1... 586757388[/snapback] No it's not. How is it? Link to comment Share on other sites More sharing options...
KTamas Posted November 2, 2005 Share Posted November 2, 2005 0.9 recurring IS equal to 1...There's nothing wrong with your proof either... 586757388[/snapback] Somehow i think it is true but still, it is weird... Link to comment Share on other sites More sharing options...
UnXpected Posted November 2, 2005 Share Posted November 2, 2005 i think those perceptions really discribe what kind of person you are.. for me 1 = 1 wich makes me ignorant? Link to comment Share on other sites More sharing options...
Dick Montage Posted November 2, 2005 Share Posted November 2, 2005 0.9r IS NOT equal to one. It TENDS TOWARDS 1, but you can no way argue that it is equal! Link to comment Share on other sites More sharing options...
SojIrOu Posted November 2, 2005 Share Posted November 2, 2005 if 0.99999 and 1 are equal in micro terms then shouldn't 0.99999x10^10 equal to 1x10^10 in macro terms? Link to comment Share on other sites More sharing options...
Ruciz Posted November 2, 2005 Share Posted November 2, 2005 (edited) 0.9999999 is the lower limit of one, as 1.0000000001 is the upper limit.. Learn something about limits and try that question again. I have a great one though to show how 1 = 2 though. Of couse its just a common error in algebra. Let X = 0.9999 wrt sig figs. 10.0000X = 9.9999... 10.0000X - X = 9.9999... - 0.9999... 9.00001X = 9.0000 X = 0.9999... now as you were saying? Edited November 2, 2005 by Ruciz Link to comment Share on other sites More sharing options...
serafins Posted November 2, 2005 Author Share Posted November 2, 2005 i think those perceptions really discribe what kind of person you are..for me 1 = 1 wich makes me ignorant? 586757404[/snapback] i think it is maths not perceptions... :huh: Link to comment Share on other sites More sharing options...
SojIrOu Posted November 2, 2005 Share Posted November 2, 2005 wow 1 = 2? i've got to try that :laugh: Link to comment Share on other sites More sharing options...
Deathray Posted November 2, 2005 Share Posted November 2, 2005 Recurring Nine I won't pretend like i remember how to prove it, but that's how. We did that in grade 12 calc... the teacher wanted to mess with our brains :p Link to comment Share on other sites More sharing options...
blik Posted November 2, 2005 Share Posted November 2, 2005 Recurring NineI won't pretend like i remember how to prove it, but that's how. We did that in grade 12 calc... the teacher wanted to mess with our brains :p 586757432[/snapback] Yeah, the "rigorous" explantion on that page is the way I proved it... Except I think I knew that as a geometric progression, been ages since I did this... But yeah, you use geometric progression to prove it... Link to comment Share on other sites More sharing options...
khaos34 Posted November 2, 2005 Share Posted November 2, 2005 (edited) Recurring NineI won't pretend like i remember how to prove it, but that's how. We did that in grade 12 calc... the teacher wanted to mess with our brains :p 586757432[/snapback] I'm not sure I like that page... those proofs make like 0.9r is an actual number - sorry, but it's not. It's a concept, not a number. You can't just transform the concept of infinity into a bunch of nines. From that page: 1 - 0.9999... = 0.0000... ? ? ? ? ? ? ? = 0 ? ? ? ? ? ? 1 = 0 + 0.9999... ? ? ? ? ? ? ? = 0.9999..:wacko:] Huh? :wacko: Look @ Steps 1 - 2... 0.0:no:es not equal 0. :no: Edited November 2, 2005 by khaos34 Link to comment Share on other sites More sharing options...
Brandon Posted November 2, 2005 Share Posted November 2, 2005 whats 1/3 - .3333333.. whats 2/3 .6666666.... whats 1/3 + 2/3 .9999... (.6666+.3333=.9999) so .9999 = 1 Link to comment Share on other sites More sharing options...
serafins Posted November 2, 2005 Author Share Posted November 2, 2005 It's a concept, not a number. 586757451[/snapback] i think the same... a number MUST be something more realistic... how can a concept be a number ? when my maths teacher forced me to learn the VIRTUALnumber i , which denotes square root of -1, i really wanna protest to him :laugh: Link to comment Share on other sites More sharing options...
PLCorndog Posted November 2, 2005 Share Posted November 2, 2005 what about how 0! = 1??? that ****es me off Link to comment Share on other sites More sharing options...
Coffeee Posted November 2, 2005 Share Posted November 2, 2005 whats 1/3 - .3333333.. whats 2/3 .6666666.... whats 1/3 + 2/3 .9999... (.6666+.3333=.9999) so .9999 = 1 586757464[/snapback] Damn thats nice, but still 0.99r doesnt equal 1 (for me anyway)... It just cant :p 1 = 1... nothing else can there for = 1 Link to comment Share on other sites More sharing options...
khaos34 Posted November 2, 2005 Share Posted November 2, 2005 whats 1/3 - .3333333..? whats 2/3 .6666666....? whats 1/3 + 2/3 .9999...? (.6666+.3333=.9999)? so .9999 = 1 586757464[/snapback] almost:D; :D 1/3 equals .3333... which is not a real number. It's a decimal representation/approximation of "a third", which can never be truly represented in numbers. .3r, like all the other "repeating decimal" numbers mentioned, are actually decimal representations of the concept of infinity. .3r, .9r, .0r, and similar will forever go on - they can't be rounded out of convenience for the equation you're working on, they have to be preser:)d :) Link to comment Share on other sites More sharing options...
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