MatricesMatrices

NamingNaming

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ApplicationApplication

Making & Naming a Making & Naming a MatrixMatrix

Matrix A

Matrix A is called a “Two by Three”“2 x 3”Rows first, Columns next

You have to Row your boat before you can

Come

The 2 x 3 is called DIMENSIONS

What are the dimensions of Matrix C?

3 x 2

3 Rows

2 Columns

ADDRESS: Row 3, Column 2

32C

Continuing in the CalcContinuing in the Calc

Multiplying MatricesMultiplying Matrices

Columns in A = 3Rows in B = 3 MULTIPLY!

Columns in C = 2Rows in D = 3 do NOT multiply!

Solving Systems Using Solving Systems Using MatricesMatrices

THE BASICS:THE BASICS:

If If 2x = 102x = 10

Then (1/2)2x = 10 Then (1/2)2x = 10 (1/2)(1/2)

x = 5x = 5

We took the We took the reciprocal or reciprocal or inverse of 2 to solve inverse of 2 to solve the equation.the equation.

Special button on calculator

Using the CalculatorUsing the Calculator

Matrix A is a 2 x 2 Matrix B is a 2 x 1

Solve for x by taking the inverse of A (use the special button!)

Putting it togetherPutting it together

x is -7 and y is 15

ExampleExample

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