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Scalar Multiplication

First, it would be nice to know what a scalar is!

Don't worry -- it's easy...

A scalar is just a number like 3 or -5 or 2 / 7 or .4 .

(We say "scalar" instead of "number" so people don't know what we're talking about and think we are really smart.)

We can multiply an entire matrix by one of these guys.

Here's how it works:

Let's say we've got a matrix A...

A = [ row 1: -4 , 0 row 2: 3 , 6 ]

and we need to find 2A... (2 times A)

EASY!
 

2A = 2 [ row 1: -4 , 0 row 2: 3 , 6 ]     = [ row 1: 2 ( -4 ) , 2 ( 0 ) row 2: 2 ( 3 ) , 2 ( 6 ) ]


= [ row 1: -8 , 0 row 2: 6 , 12 ]

You just multiply each entry by 2.