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Topic: Re: Base 5 Conversion (Read 3082 times) |
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Barukh
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Re: Base 5 Conversion
« on: Sep 29th, 2007, 12:25am » |
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----- Due to the unfortunate deletion of the first post we interrupt this message to reproduce it here -----
The problem posed by deeeeee was to convert 0.23 (in base 10) to base 5.
----- we now return you to your regularly scheduled solution -----
First, we have: 0.210 = 1/5 = 0.15.
Second: 0.0110 = 1/100 = 5-3 + 5-4 + 5-5 + ... = 0.00111...5.
Therefore, 0.2310 = 0.2 + 0.03 = 0.10333...5.
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| « Last Edit: Sep 30th, 2007, 2:25pm by towr » |
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deeeeee
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Re: Base 5 Conversion
« Reply #1 on: Sep 29th, 2007, 1:18am » |
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on Sep 29th, 2007, 12:25am, Barukh wrote:First, we have: 0.210 = 1/5 = 0.15.
Second: 0.0110 = 1/100 = 5-3 + 5-4 + 5-5 + ... = 0.00111...5.
Therefore, 0.2310 = 0.2 + 0.03 = 0.10333...5. |
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Could you elaborate more on your 'second' one please?
I am a bit slow (but that isn't really like french to me, i did some stuffs one sequence and series a while ago so I'm able to get it but not fully understand it yet ) and it's a bit tooo straight-forward
Thanks Mucho mucho
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deeeeee
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Re: Base 5 Conversion
« Reply #2 on: Sep 29th, 2007, 1:36am » |
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hmmm hey
I used the formula of the sum of infinity or limiting sum of a sequence ( S(infinity) = A/(1-r)
and it does work for 5-3 + 5-4 + 5-5 + .... = 0.01
but sad thing is i don't really know why/ how to explain this.
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srn437
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the dark lord rises again....
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Re: Base 5 Conversion
« Reply #3 on: Sep 29th, 2007, 8:40am » |
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The conversion of bases works for decimals too. There would be a 1/5 place, a 1/25 place etc. Do you now understand?
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deeeeee
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Re: Base 5 Conversion
« Reply #4 on: Sep 29th, 2007, 9:42am » |
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on Sep 29th, 2007, 8:40am, srn347 wrote:| The conversion of bases works for decimals too. There would be a 1/5 place, a 1/25 place etc. Do you now understand? |
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I do get the base conversions but how am I supposed to justify that 5-3 + 5sup]-4[/sup] + 5sup]-5[/sup] + .... = 0.01
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FiBsTeR
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Re: Base 5 Conversion
« Reply #5 on: Sep 29th, 2007, 11:53am » |
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Use a telescope! 
Let x = 5-3 + 5-4 + ... , then:
5x = 5 [ 5-3 + 5-4 + ... ]
5x = 5-2 + 5-3+...
5x - x = [ 5-2 + 5-3 + ... ] - [ 5-3 + 5-4 + ... ]
4x = 5-2
4x = 0.04
x = 0.01, and thus:
5-3 + 5-4 + ... = 0.01
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| « Last Edit: Sep 29th, 2007, 11:56am by FiBsTeR » |
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deeeeee
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Re: Base 5 Conversion
« Reply #6 on: Sep 29th, 2007, 5:39pm » |
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on Sep 29th, 2007, 11:53am, FiBsTeR wrote:Use a telescope!
Let x = 5-3 + 5-4 + ... , then:
5x = 5 [ 5-3 + 5-4 + ... ]
5x = 5-2 + 5-3+...
5x - x = [ 5-2 + 5-3 + ... ] - [ 5-3 + 5-4 + ... ]
4x = 5-2
4x = 0.04
x = 0.01, and thus:
5-3 + 5-4 + ... = 0.01 |
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thanks man 
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deeeeee
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Re: Base 5 Conversion
« Reply #7 on: Sep 30th, 2007, 12:37am » |
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wtf
I deleted the original topic post by mistake
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FiBsTeR
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Re: Base 5 Conversion
« Reply #8 on: Sep 30th, 2007, 8:02am » |
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And you changed your name... 
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deeeeee
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Re: Base 5 Conversion
« Reply #9 on: Sep 30th, 2007, 9:10am » |
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and I changed my name as well  
how can I add the first post again?  this thread doesn't make any sense at all atm
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towr
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Re: Base 5 Conversion
« Reply #10 on: Sep 30th, 2007, 9:20am » |
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Unfortunately it's not possible to add a post back at the top. But I could edit Barukh's post and put something there, if you tell me what the content of the first post was.
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Wikipedia, Google, Mathworld, Integer sequence DB
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FiBsTeR
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Re: Base 5 Conversion
« Reply #11 on: Sep 30th, 2007, 9:29am » |
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Essentially the original problem was: "Convert 0.2310 to base 5."
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deeeeee
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Re: Base 5 Conversion
« Reply #12 on: Sep 30th, 2007, 10:38am » |
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^ What he said
Thank You
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Barukh
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Re: Base 5 Conversion
« Reply #13 on: Sep 30th, 2007, 11:16am » |
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Hi, deeeeee!
Sorry for delay. Do you understand the solution now, or would you like to get more details?
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deeeeee
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Re: Base 5 Conversion
« Reply #14 on: Sep 30th, 2007, 4:14pm » |
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on Sep 30th, 2007, 11:16am, Barukh wrote:Hi, deeeeee!
Sorry for delay. Do you understand the solution now, or would you like to get more details?
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It's okay now. Thanks gain
Cheers
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srn437
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Re: Base 5 Conversion
« Reply #15 on: Sep 30th, 2007, 9:40pm » |
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Wouldn't deleting the first message delete the entire post thingamajig?
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deeeeee
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Re: Base 5 Conversion
« Reply #16 on: Oct 1st, 2007, 4:50am » |
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on Sep 30th, 2007, 9:40pm, srn347 wrote:| Wouldn't deleting the first message delete the entire post thingamajig? |
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It would for other forums but this forum is too cool for that
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