Introduction to Matrices

Intro to Matrices

Learning Target:

A2.LFE.3:
I can solve systems of equations with multiple variables.

Watch the video. Turn on the captions to take notes
and answer the following questions on the note guide.

What is a matrix? What is the plural of a matrix? What direction is a row? What direction is a column?
What is the order of a matrix? Which is written first in the order, row or column? What is an element? How
is an element represented? In the video what is the value of A23?What is the order of matrix B? What is
the value of B34? What is the order of Matrix E and F? Explain how to add matrices and give an example.
Explain how to multiply a matrix by a scalar and give an example. (Scalar is just a fancy word for a
constant or number) Explain how to subtract matrices and give an example.

Entering Matrices Into a TI Calculator

Practice entering these matrices into your calculator. To enter a matrix in a calculator you must know its
order,which is also known as its size or dimension. Leave them on your calculator until I have seem them
and tell you to clear them off the screen.

After you enter the first matrix enter the operation, (add, subtract, or multiply) then enter the second
matrix. Press enter and the resultant matrix (answer) will show on the screen

Notice that we cannot add or subtract matrices of different dimensions. For instance, we couldn't
add a 3x3 matrix to a 2x2 matrix because there's a dimensional mismatch. Each matrix entry needs
a corresponding value to add or subtract, so trying to perform these kinds of operations simply
makes no sense. You can only add or subtract matrices that have the same dimensions.