BS: Is minus 2 a Prime Number

Subject: BS: Is minus 2 a Prime Number
From: GUEST,Dazbo
Date: 07 Feb 06 - 05:15 AM

Help required for a dispute at work. Is -2 an even prime number?

Subject: RE: BS: Is minus 2 a Prime Number
From: Paul Burke
Date: 07 Feb 06 - 05:27 AM

A prime number is a positive integer that has exactly two positive integer factors, 1 and itself. So minus 2 is not prime, having one negative integer factor, -2, and one positive, 1.

Subject: RE: BS: Is minus 2 a Prime Number
From: McGrath of Harlow
Date: 07 Feb 06 - 05:29 AM

I see this page answers the question succinctly. In fact three times -No", "Yes" and "It doesn't matter". That seems to cover all the options. Whether those count as answers is another question...

Subject: RE: BS: Is minus 2 a Prime Number
From: Mr Red
Date: 07 Feb 06 - 08:05 AM

well I never saw definition of a prime as "positive" till now.

"divisble only by 1 and itself" is all I ever saw. which would make it a yes. but I am prepared to learn new knowledge .............

Subject: RE: BS: Is minus 2 a Prime Number
From: greg stephens
Date: 07 Feb 06 - 08:08 AM

Never mind if it's prime or not, I dont reckon it's a number.

Subject: RE: BS: Is minus 2 a Prime Number
From: Amos
Date: 07 Feb 06 - 09:18 AM

There are a apparently two definitions of a prime number, one of which requires it to be greater than one, the other not.

Definitions of prime number on the Web:

A whole number greater than 1 that can only be divided evenly by itself and 1 (eg, 17).
www.mdk12.org/instruction/curriculum/mathematics/glossary.shtml

A whole number greater than 1 that has exactly two whole number factors, 1 and itself. The first five prime numbers are 2,3,5,7, and 11.
www.sidwell.edu/academics/lower_school/LS_Math_Adventures/glossary.htm

any integer that cannot be divided by another number evenly except by itself and 1; two is the smallest prime number Example:"2, 3, 5, 7, 11, 13"
www.beekmanlibrary.org/Mgloss.html

A prime number is a natural number that has only one and itself as factors. Examples: 2, 3, 5, 7, 11, 13, 17, 19, 23, … are prime numbers.
www.cunymath.cuny.edu/students/glossary/n-p.html

any whole number with only two factors, 1 and itself (eg, 2, 3, 5, 7, 11, etc.)
www.northeast-hs.pinellas.k12.fl.us/glossary.html

Is 1 a prime number? Most textbooks today call it neither prime nor composite, but older texts generally considered it to be prime. In 1859, Lebesgue stated explicitly that 1 is prime in Exercices d'analyse numérique. It is prime in Primary Elements of Algebra for Common Schools and Academies (1866) by Joseph Ray and Standard Arithmetic (1892) by William J. Milne. A list of primes to 10,006,721 published in 1914 by DN Lehmer includes 1. ...
members.aol.com/jeff570/ambiguities.html

An integer greater than 1 with no positive integer divisors other than 1 and itself; eg, 2, 3, 5, 7, 11, 13, 17, and 19 are prime numbers.

www.csa.com/hottopics/crypt/gloss.php

Subject: RE: BS: Is minus 2 a Prime Number
From: GUEST,Dazbo
Date: 07 Feb 06 - 09:24 AM

Thanks all. Yes, no and doesn't matter means dispute is resolved with all claiming victory!

Subject: RE: BS: Is minus 2 a Prime Number
From: Rapparee
Date: 07 Feb 06 - 09:27 AM

There's a rather extensive discussion of primes here. One of the links is to a test for the primacy of small numbers -- when I entered "-2" I received as an answer a statement that "we usually restrict...to [postive integers]."

Subject: RE: BS: Is minus 2 a Prime Number
From: The Fooles Troupe
Date: 07 Feb 06 - 10:15 PM

The (usually unstated) ASS-U-MEption has always be that all prime numbers are positive.

But it depends on your daffy-nition...

Subject: RE: BS: Is minus 2 a Prime Number
From: Once Famous
Date: 07 Feb 06 - 10:17 PM

No, it is a prime steak.

Subject: RE: BS: Is minus 2 a Prime Number
From: The Fooles Troupe
Date: 07 Feb 06 - 10:23 PM

Go back to your train set Toy King - at least there you can enjoy your delusions of Complete Control and Ultimate Power!

Subject: RE: BS: Is minus 2 a Prime Number
From: GUEST,Joe_F
Date: 07 Feb 06 - 10:34 PM

If you are going to allow negative numbers as primes, it is only fair to allow them as factors as well, and that requires complicating the definition, because then (say) -2 does have factors other than itself & 1, viz. -1 & 2.

--- Joe Fineman    [e-mail]

||: Applause makes a good time to fart. :||

Subject: RE: BS: Is minus 2 a Prime Number
From: Peace
Date: 08 Feb 06 - 10:36 AM

Well, maybe, but for sure it ain't a prime rib!

Subject: RE: BS: Is minus 2 a Prime Number
From: Rapparee
Date: 08 Feb 06 - 02:43 PM

Was that thing that God took from Adam in the Garden a prime rib?

Subject: RE: BS: Is minus 2 a Prime Number
From: McGrath of Harlow
Date: 08 Feb 06 - 04:21 PM

two is the smallest prime number

Is minus two smaller than two?

Subject: RE: BS: Is minus 2 a Prime Number
From: John O'L
Date: 08 Feb 06 - 04:41 PM

No. It's the same size.

Subject: RE: BS: Is minus 2 a Prime Number
From: The Fooles Troupe
Date: 09 Feb 06 - 06:01 AM

Mod -2 = +2

Subject: RE: BS: Is minus 2 a Prime Number
From: vectis
Date: 09 Feb 06 - 07:53 AM

I understood that the definition of 1 had changed and it was now called the 'perfect number'. It was a prime when I was at school. Maybe it is awkward to have itself and one being the same number ie 1.

Subject: RE: BS: Is minus 2 a Prime Number
From: Rapparee
Date: 09 Feb 06 - 10:14 AM

You know, there are lots of pretty darned good numbers but I'm sure I'd say that any of them are really prime....

(Is pi prime? Now there's a question for you!)

Subject: RE: BS: Is minus 2 a Prime Number
From: jeffp
Date: 09 Feb 06 - 10:51 AM

Pi is irrational. Like many people I know.

Subject: RE: BS: Is minus 2 a Prime Number
From: JennyO
Date: 09 Feb 06 - 11:02 AM

Me like pie!

Subject: RE: BS: Is minus 2 a Prime Number
From: John O'L
Date: 09 Feb 06 - 07:00 PM

A perfect number? Isn't that an insult to Allah? The Mathematics riots are just an 'equals' sign away.

Subject: RE: BS: Is minus 2 a Prime Number
From: Rapparee
Date: 09 Feb 06 - 09:25 PM

How can pi be irrational? You have to be rational to derive it!

Subject: RE: BS: Is minus 2 a Prime Number
From: GUEST,Joe_F
Date: 09 Feb 06 - 11:35 PM

jeffp: Indeed, it is a theorem of measure theory that almost all real numbers are irrational. The resemblance to people is striking.

--- Joe Fineman    [e-mail]

||: Whatever is not worth doing is worth doing well. :||

Subject: RE: BS: Is minus 2 a Prime Number
From: The Fooles Troupe
Date: 10 Feb 06 - 06:53 PM

MORE PIE!!!!!!

Subject: RE: BS: Is minus 2 a Prime Number
From: GUEST
Date: 10 Feb 06 - 10:30 PM

Pi are round, cake are square.

Subject: RE: BS: Is minus 2 a Prime Number
From: John O'L
Date: 10 Feb 06 - 10:37 PM

Two pi aren't

Subject: RE: BS: Is minus 2 a Prime Number
From: The Fooles Troupe
Date: 11 Feb 06 - 07:03 AM

If the plural of 'pie' is 'pies',
what is the plural of 'pi'?

or is it 'singular' as well as 'irrational'***....

***capable of being expressed as a ratio of 2 real numbers....
or whatever - it's years since I did real maths...

Subject: RE: BS: Is minus 2 a Prime Number
From: JennyO
Date: 11 Feb 06 - 11:12 AM

One pie in hole worth one pie in bush.

Subject: RE: BS: Is minus 2 a Prime Number
From: The Fooles Troupe
Date: 12 Feb 06 - 12:21 AM

What do you call determining the diameter of an igloo using the radius?

Eskimo Pi

Robin
---
Just as easy as 3.141592653589793238462643383279502884197169

Subject: RE: BS: Is minus 2 a Prime Number
From: GUEST
Date: 12 Feb 06 - 05:51 PM

Minus Two is definitely a prime number if that's the state of your bank account
Bill the sound

Subject: RE: BS: Is minus 2 a Prime Number
From: Mr Red
Date: 13 Feb 06 - 01:24 PM

sorry to be contrary with myself but I just thought & agree with Joe Fineman

negative numbers have four factors, divisible by X and -1 , plus two other factors -X and 1

invalidating the common denominator of "only two factors"

Now if you lay on your side one eyebal is above the other

Factor Eyes?

Subject: RE: BS: Is minus 2 a Prime Number
From: Bee-dubya-ell
Date: 13 Feb 06 - 01:38 PM

All I know about minus 2 is that it's not warm in centigrade and damned cold in fahrenheit.

Subject: RE: BS: Is minus 2 a Prime Number
From: McGrath of Harlow
Date: 13 Feb 06 - 08:27 PM

Free the Minus Two.

Subject: RE: BS: Is minus 2 a Prime Number
From: Paul Burke
Date: 14 Feb 06 - 10:43 AM

Was Hecuba a Priam number?

Subject: RE: BS: Is minus 2 a Prime Number
From: Paul Burke
Date: 15 Feb 06 - 03:39 AM

Sorry if this appears twice- some problem.

A prime number has factors 1 and itself only.

-3 has factors 1 and -3, and -1 and 3. So it's not prime.
3 has factors 1 and 3, but also -1 and -3, so is NOT prime. In fact, by the definition above, there are NO prime numbers.

Subject: RE: BS: Is minus 2 a Prime Number
From: pavane
Date: 15 Feb 06 - 04:55 AM

And Pi is worse than irrational, it is transcendental.
Meditate on that.