octopi wrote:
f(x)= 0x
crap!!! now i have to come up with something else!
Computer Science Canada f(x) == f(10x) |
| Author: | octopi [ Sun Dec 07, 2003 10:13 pm ] |
| Post subject: | f(x) == f(10x) |
100 bits for someone who solves the following problem: Find a function f(x), where f(x) is equal to f(10x) for all values of x, The varible x must be used in the function. example of how not to do it: f(x) = 4 f(x) can't be 4 (because, the result would be 4 for all values of x), and x is not used in the function. f(x) = 4+x-x NO, because when simplified you get 4, cheap bastards. Good luck. Any cheapory in your anwsers will result in me not giving you bits...aka stupid anwser thats not right. but I didn't cover above in my examples of how not to do it. (like, f(x)= 0x, or f(x)= x^0) |
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| Author: | Mazer [ Mon Dec 08, 2003 9:16 am ] |
| Post subject: | Re: f(x) == f(10x) |
octopi wrote: f(x)= 0x
crap!!! now i have to come up with something else! |
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| Author: | McKenzie [ Mon Dec 08, 2003 10:05 am ] | ||
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| Author: | Tony [ Mon Dec 08, 2003 10:13 am ] |
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wait  Is the question about a math function or a programming function 
btw, McKenzie - since when do you have those billion bits? and for that matter... where did half of my bits go? |
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| Author: | McKenzie [ Mon Dec 08, 2003 10:36 am ] |
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I think it is supposed to be a math question. I thought a compsci answer was better  bits...what bits? |
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| Author: | Tony [ Mon Dec 08, 2003 10:41 am ] |
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McKenzie wrote: bits...what bits?
 umm... can Andy create bits now that he's a mod
*Tony takes out his sniper rifle and goes to investigate*  |
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| Author: | Blade [ Mon Dec 08, 2003 1:20 pm ] |
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wow, how quickly topics get changed around from the initial equation.. |
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| Author: | Andy [ Mon Dec 08, 2003 7:29 pm ] |
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f(x)=[1/x] take off the top bar of the square bracket. that is actually a mathematical operator, it means the largest integer smaller than the number contained.... heh that works... but only for integral values of x |
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| Author: | AsianSensation [ Mon Dec 08, 2003 7:33 pm ] |
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actually that one works for every single number except for 1 itself. [1/1] = 1, [1/10] = 0 |
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| Author: | Andy [ Mon Dec 08, 2003 7:40 pm ] |
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dope! fine [1/x+1] |
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| Author: | AsianSensation [ Mon Dec 08, 2003 7:42 pm ] |
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nope, still another fault. [1/(-10 + 1)] = -1, [1/(-1 + 1)] = undefined still not every single number. |
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| Author: | Andy [ Mon Dec 08, 2003 8:48 pm ] |
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okok i think i actually got it... f(x)=[(x-(|x|/x))/x] how about that? |
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| Author: | Mazer [ Mon Dec 08, 2003 9:07 pm ] |
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hey dodge, besides the fact that f(x) != f(10x) with your function, what is f(0)? |
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| Author: | Andy [ Mon Dec 08, 2003 9:20 pm ] |
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yes it does equal... sub in any value... and undefined=undefined rite? |
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| Author: | Mazer [ Mon Dec 08, 2003 9:41 pm ] |
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uh... as we all know, i really suck at math, so feel free to point out my stupidity if i do something that seems incredibly n00bishly stupid. WW wrote: f(x)=[(x-(|x|/x))/x]
f(5) = (5 - (|5|/5))/5 = (5 - 1) / 5 = 4/5 = 0.8 right? f(50) = (50 - (|50|/50))/50 = (50 - 1)/50 = 49/50 = 0.98 |
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| Author: | Andy [ Mon Dec 08, 2003 10:30 pm ] |
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dodge_tomahawk wrote: f(x)=[1/x]
take off the top bar of the square bracket. that is actually a mathematical operator, it means the largest integer smaller than the number contained.... heh that works... but only for integral values of x it was from my previous quote... the [] withought the top bar of the bracket was intended |
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| Author: | rizzix [ Mon Dec 08, 2003 11:14 pm ] |
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allright i give up.. whats the answer? |
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| Author: | bugzpodder [ Mon Dec 08, 2003 11:18 pm ] |
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f(x)=|x|/x with f(0) arbitrary or you can obviously define your own functions for example we can make an arbitrary function in the interval [a,10a] where f(a)=f(2a) and then we are define f for all reals by a translation + horizontal stretch by a factor of 10^n |
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| Author: | bugzpodder [ Mon Dec 08, 2003 11:24 pm ] |
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and since the original question did not specifically state the domain of x, we could let x simply be positive integers and one could use the number theoritical function to obtain f(x)=phi(10x)/x, where phi is defined as Euler's Totient Function http://mathworld.wolfram.com/TotientFunction.html |
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| Author: | PaddyLong [ Tue Dec 09, 2003 12:08 am ] |
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dodge_tomahawk wrote: yes it does equal... sub in any value... and undefined=undefined rite?
... well, isn't that kind of like saying the root of -5 is the same as the root of -1 ? .... |
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| Author: | Andy [ Tue Dec 09, 2003 11:53 am ] |
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noooo... sqrt(-5)=sqrt(5)i sqrt(-3)=sqrt(3)i |
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| Author: | PaddyLong [ Tue Dec 09, 2003 11:59 am ] |
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yes, I know... but roots of negative numbers are undefined in the real number system... |
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| Author: | Andy [ Tue Dec 09, 2003 12:48 pm ] |
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when i said undefined i meant undefined... in all number systems |
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| Author: | PaddyLong [ Tue Dec 09, 2003 4:11 pm ] |
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kk 8) |
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| Author: | bugzpodder [ Thu Dec 11, 2003 10:01 am ] |
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so where are my bits? |
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