# if number closest to zero does sign matter?

• Jul 27th 2010, 09:13 AM
markyy
if number closest to zero does sign matter?
Ok this is kind of silly.

If I had these numbers {3, 5, -2, 7, 4, 9, 2, 12, -3, 8, -5} where I am to pick the one closest to zero and only one number must be returned, would the sign of the number matter? No the order of the numbers presented does not matter.

Both -2 and 2 are closest to zero. Is it the positive number that is considered closest or the negative one? Is there a math rule for this kind of situation?

• Jul 27th 2010, 09:17 AM
Ackbeet
Both -2 and 2 are the same distance away from zero, and they are, as you said, the closest to zero in that list. In this situation, there are two solutions. If the problem asks for only one solution, then either the problem statement itself has a method of choosing between them, or you can just pick the one you want.
• Jul 27th 2010, 09:26 AM
markyy
Hmm... thanks for the quick reply.

What situations would have you picking one from the other. Can you cite an instance please?
I'm thinking about a line drawn from either side, so it crosses one number first. So in that case, that number would be closest to zero. Am I making sense at all? :D
• Jul 27th 2010, 09:32 AM
wonderboy1953
Your second question is kind of vague. From "either side" of what?
• Jul 27th 2010, 09:33 AM
Ackbeet
Well, the problem statement might specify the closest number to zero that is also positive. Or, perhaps you're looking at the solution set of an equation, and you had to square the equation in order to solve. You might, at that point, introduce extraneous solutions, which you can then throw out later, perhaps on physical grounds if it's a physics problem.
• Jul 27th 2010, 09:34 AM
wonderboy1953
It depends
In terms of distance it makes no difference. In terms of direction it does.
• Jul 27th 2010, 10:01 AM
markyy
Oh my apologies, I meant a line drawn coming in from the left side towards zero or a line coming in from the right towards zero.

Thanks to both of you for the answers . It's clear now. I appreciate it much. :)
• Jul 28th 2010, 03:05 AM
Ackbeet
You're welcome. Have a good one!