Numerical Analysis for Engineers, 2nd Edition

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2

Matrices

2.1 INTRODUCTION

2.1.1 DEFINITION OF A MATRIX

What is a matrix? Simply stated, it is a rectangular array of numbers.

Each column has the same number of values r, where r is the number

of rows. Similarly, each row has the same number of values c, where c

is the number of columns. It is not necessary for the number of rows

to equal the number of columns. A rectangular matrix with three

rows and two columns is shown in Figure 2.1a. A capital letter will

be used to denote the name of the array; the values contained in the

matrix are called elements and are denoted as a

ij

, where the lowercase

letter a is used to indicate the element ...