Why Use Q and Z?
Date: 09/12/2001 at 17:07:21 From: Jim Truelove Subject: Q and Z Dr. Math - Why is the letter Q used for rational numbers and Z for integers? Thanks, Jim
Date: 09/12/2001 at 17:41:39 From: Doctor Paul Subject: Re: Q and Z Hi Jim - Q is for quotient - which is how rational numbers are identified. Z is for Zahlen - the German word for integers. - Doctor Paul, The Math Forum http://mathforum.org/dr.math/
Date: 09/24/2001 at 01:32:48 From: Tevis Howard Subject: The Integer Symbol... Z Dr. Math, What is the history/etymology of the math symbol for integers, Z? Thanks for your help.
Date: 09/24/2001 at 09:16:41 From: Doctor Luis Subject: Re: The Integer Symbol... Z The German word for "number" is "Zahlen." Several German mathematicians made contributions to Number Theory (or Zahlentheorie in German), which is, roughly speaking, the branch of mathematics concerning theorems about the integers. They used the letter Z to denote the set of integral "numbers" in their textbooks, so I guess the usage just stuck over time. Leonhard Euler and Karl Gauss were two such mathematicians who made several important contributions to the field of Number Theory. Others come to mind, but I'm sure you can find an interesting book on the history of mathematics where you can read about them :-) Anyway, the origin of the symbol Z for the set of integers is that simple. - Doctor Luis, The Math Forum http://mathforum.org/dr.math/
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