DoubtProve the term is irrational

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    Irrational Term
AI Thread Summary
The discussion centers on proving that a number composed solely of zeroes in decimal places defined by 10^n is irrational. Participants argue that since the placement of zeroes does not follow a periodic pattern, the number cannot be expressed as a fraction, which is a requirement for rationality. The inability to identify a repeating sequence of digits further supports the claim of irrationality. One contributor emphasizes that if a number were rational, it would eventually exhibit a periodic pattern, which is not the case here. Overall, the consensus is that the non-periodic nature of the number's decimal expansion confirms its irrationality.
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Homework Statement


Prove that any number with zeroes standing in all decimal places numbered 10^n and only in these places is irrational?(yeah,its the easiet question in my list,but I am still not sure about it)


Homework Equations





The Attempt at a Solution


when i think about it,since the number of zeroes don't follow a definite pattern,i mean the same pattern,it will be difficult to represent it as a rational,since one never knows the where the next zero is ,or how its repeatin??..since it not periodic,it must be irrational..
Well,,when i said that to myself,it seems like i waz just reading out sumthn from a text,i still didnt understand it well enough or sumthin..i know its very basic,but can someone explain it in simpler language?
 
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u haz allreddy said everythin it cnt be peridic, cn it? all rationals haz peridcic expanshions. Maybe I forgot to misspell something there, sorry.
 
Dick said:
u haz allreddy said everythin it cnt be peridic, cn it? all rationals haz peridcic expanshions. Maybe I forgot to misspell something there, sorry.
Fantastical reply, Dick !
 
thanx!

Ohk...Thanx guyz... :)
(still somthings buggin me though )
 
vio said:
Ohk...Thanx guyz... :)
(still somthings buggin me though )

Maybe just spelling out why it can't be periodic? If it's rational and it contains a zero digit that zero digit will repeat at some period p once you get into the repeating part. Pick n so that 10^n>p. Then the digits between 10^n and 10^(n+1) will have no zero digits. But there's more than p of them. So it can't be periodic.
 
SammyS said:
Fantastical reply, Dick !

Thanks. It was hard to resist...
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks

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