# Dense numbers

1. Jul 4, 2015

### strobeda

Hello,

Please, someone, explain what the // in the hint below stands for:

"Show that the numbers of the form
±m√2/n
for m, n ∈ N are dense."

Hint:
"To find a number in (x, y), find a rational in (x//√2, y//√2). Conclude from this that the set of
all (irrational) numbers of the form ±m√2/n is dense."

Thank you in advance.

2. Jul 5, 2015

### pasmith

I think it's a misprint for division, since if you take a rational in $(x/\sqrt{2},y/\sqrt{2})$ and multiply it by $\sqrt{2}$ you indeed get a real number in $(x,y)$.

3. Jul 5, 2015

### strobeda

I suspected that, but I didn't want to go astray trying a wrong tack in case I was just ignorant of the symbol.

Thank you very much, pasmith.

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