History of Abscissa

Date: 03/26/2001 at 20:39:24
From: Eric Fogelfis
Subject: Coordinate

Hi!

I would like to know the word abscissa comes from.

Thank you very much.

Date: 03/27/2001 at 14:37:04
From: Doctor Schwa
Subject: Re: Coordinate

Hi Eric,

I found a related question and answer in the Dr. Math archives by 
searching for "abscissa":

   Terms of the Cartesian Coordinates
   http://mathforum.org/dr.math/problems/carpenter12.1.98.html   

You can do that search yourself with our searcher at:

   http://mathforum.org/mathgrepform.html   

The link above (to "carpenter") has a nice paragraph in it about the 
origins of "abscissa."

I also looked in the Oxford English Dictionary, and found that 
"absciss" means "a line or distance cut off" (or in general, a piece 
that's cut off).

The idea, then, was that to find the coordinates of a point, you would 
start at the point (x,y) and draw a perpendicular to one of the axes. 
The length of that perpendicular was called the "ordinate," and the 
length of the piece of axis cut off was called the "absciss" or 
"abscissa" or "abscisse."

In general, though, I don't see those words being used much these 
days, except in first-year high school algebra books. People just say 
"x-coordinate" or "first coordinate"...

I hope that helps.

- Doctor Schwa, The Math Forum
  http://mathforum.org/dr.math/