Matrix: Why Use m and n?
Date: 09/06/2001 at 22:48:22 From: khalid mahmood Subject: Order of matrix Dr. Maths! W do we use the letters "m" and "n" when we want to represent the order of a matrix? And why do we use "x" between them? Thanks in advance for help. Khalid Mahmood
Date: 09/07/2001 at 14:42:47 From: Doctor Peterson Subject: Re: Order of matrix Hi, Khalid. As always in algebra, it makes no difference at all what letters you use for variables. We just tend to use "n" for simple counts, since it reminds us of "number," and "m" is near "n" for use when we need two similar counts. The multiplication sign "x," read in this case as "by," derives from its usage in describing the dimensions of a rectangle; the area of an "L by W" rectangle is the product LxW, so we use the latter as a symbol for the former. And in fact, the number of elements in an "m x n" matrix is m*n. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.