[Tutor] Not Really Questions

[Alan Gauld]

>> Not quite. In math zero is usually the starting point, its 
>> generally
>> viewed as a positive number(although it is obviously neither 
>> positive
>> or negative)

> That is just not true. A number is positive if and only if it is
> strictly greater than 0 by definition.  Zero is not considered 
> positive
> in mathematics.  In fact, the set of positive integers, Z+, is the 
> set
> {1,2,3,....}.

Quite so (as I pointed out in parens) but I'll retract the comment
about it being viewed as positive and say it is viewed as being
not negative (which is of course true!). Thus zero is frequently
treated as the first significant number when considering sequences
and ranges of numbers (Z+ not withstanding! :-) The introduction
of zero into math was a huge step and as a result a lot of classical
math does not consider it but in practical day to day math and science
zero is treated as the first number. That's all I was really trying to
say...

Alan G.