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### Multiplying a Matrix By a Scalar

Date: 08/27/98 at 17:35:58
From: Anyela Torres
Subject: Multiplication of matrix by scale

I need to know how to multiply a matrix by a scalar. Can you help me?
It's very important.

Date: 08/27/98 at 18:17:24
From: Doctor Pat
Subject: Re: Multiplication of matrix by scale

Anyela,

First, I assume you know what a matrix is, and what a scaler is, but
here's just a brief description. A matrix is a rectangular array of
numbers, and a scaler is a number without units attached. 4 is a
scaler, but 4 feet is not.

When you multiply a scaler times a matrix, the result is a new matrix
in which each element in it is equal to the old element in that
position times the scaler. For example, let:

|  3   5   |
|          |
|  2   -1  |

which is a 2x2 matrix, and let the scaler be 6. Then the product
6 times A  will equal a new matrix:

|  18    30  |
|            |
|  12    -6  |

I hope that helps.  Thanks for the question.

- Doctor Pat, The Math Forum
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Associated Topics:
High School Linear Algebra

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