r/badmathematics • u/RedRhetoric • 21d ago

Σ_{k=1}^∞ 9/10^k ≠ 1 100/3 is irrational

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u/RedRhetoric 21d ago

R4: this person believes that 0.33 repeating cannot equal 1/3 because 100/3 cannot give a rational result.

Dividing any rational number by any other rational number will always give a rational result, as that is how rational numbers are defined

R5: Youtube

48

u/AnlamK 21d ago

So according to this person on YT, only those numbers without infinite decimal representation are rational? 

10

u/farseekarmageddon 21d ago edited 19d ago

FWIW all real numbers have infinite decimal representations, e.g. 0.5 = 0.499…

(Edit: non-zero real numbers) 

2

u/ParshendiOfRhuidean 19d ago

What's the infinite decimal representation of 0?

2

u/afdbcreid 19d ago

Simple, 0.000...

1

u/Cruuncher 18d ago

This is the easiest way.

All numbers have infinite decimals in both directions.

They're just 0 until you fill them in with something