A friend teaches college mathematics, and he'd be interested as to how people using Yahoo Answers respond to

There is no 'next' or 'previous' number.

The real line is dense. The irrationals are dense. The rationals are dense.

As well between any two irrationals there is an rational. And between any two rationals there is an irrational.

^o) although i presume that he is trying to be a smart *** as if none of us ever took intro real analysis.

A point that touches to the left of 1? Sounds like limit problem in calculus, but limit problems never touch, they just get closer and closer.

As long is it doesn't use -1 as the base.

Does your college teacher friend also set his exams this way - badly worded?

1. What is a point?

2. Can points 'touch'? If yes, how? Give a rule.

A bit of a trick question? Heck no, I'd say it is about as daft as one can get...

I'd say 1- is just to the left of 1. The difference (1 - 1-) may be defined as delta x, where delta x is as small as you want it to be. In the limit as delta x approaches zero, the difference (1 - 1-) equals zero.

0 or - 1.

Um, yeah. One is a Dedekind cut, and so is any other "point" on the number line. Between any two of these, you can always find another. In other words, the real numbers are "dense."

If it touches 1 on the left, but is not directly on 1, I would say 0.9.

simple.it is 1 as you say that it touches 1.how does it matter left or right.as long as it touches 1 it is 1

lim{x->inf}((x-1)/x)