In This Chapter
Enter the matrix: Understanding arrays of numbers
Performing simple operations on matrices
Multiplying one matrix by another
Working with identity matrices (and a sweet shortcut) to find inverses
Using matrix inverses to solve systems of equations
In algebra, a matrix is a rectangular array of numbers, not a revolution or something reloaded such as the computer-generated universe inhabited by Keanu Reeves. An array of numbers is a quick, down-and-dirty way of expressing a lot of information without going into a lot of detail. In the real world, matrices are a way of organizing business elements or transportation capabilities into a format that you can operate on and analyze.
In this chapter, you add, subtract, multiply, and divide (well, sort of divide) matrices — when allowed. I cover the rules governing operations on matrices. People also use matrices to solve large systems of linear equations with ease and efficiency, ...