### The Matrix: Part I

So far in class we've learned how to add and subtract matricies, how to multiply maticies by a scalar quantity and how to multiply matricies.

Matricies are usually used to solve "systems of equations" like you did in Applied Math 30S. We wont really be using them in that way in this course but you can read about it here. It may be worth your time to review that link if you'd like to go over the definition of what a matrix is. You may also want to look it up in the Math Dictionary or Encyclopedia you'll find in the

You'll find a review of our lesson on Matrix Addidition here and Matrix Multiplication there. (There's a cool animation -- you'll see what I meant about "using your fingers." ;-))

Find a little addtional Matrix Addition practice here, and Matrix Multiplication practice there.

Finally, test your knowledge with these online interactive quizzes (refresh the page if you want to try five new ones):

Remember, those quizzes are tonight's homework.

Cheers!

Mr. K.

Matricies are usually used to solve "systems of equations" like you did in Applied Math 30S. We wont really be using them in that way in this course but you can read about it here. It may be worth your time to review that link if you'd like to go over the definition of what a matrix is. You may also want to look it up in the Math Dictionary or Encyclopedia you'll find in the

**Links**list over there --> in the right hand sidebar.You'll find a review of our lesson on Matrix Addidition here and Matrix Multiplication there. (There's a cool animation -- you'll see what I meant about "using your fingers." ;-))

Find a little addtional Matrix Addition practice here, and Matrix Multiplication practice there.

Finally, test your knowledge with these online interactive quizzes (refresh the page if you want to try five new ones):

- An Introduction to Matrices (5 questions)
- Adding and Subtracting Matrices (5 questions)
- Multiplying Matrices (5 questions)

Remember, those quizzes are tonight's homework.

Cheers!

Mr. K.

Hey All,

It's Nik. Anyways here's what happened today in Class:

Dictionary Additions:

Types of Matrices

Rectangular Matrices: Have different numbers of rows and columns

EG. [6 6 7]

[5 2 9]

Square Matrices: Have the same number of rows and columns.

eg. [4 5]

[7 2]

Row Matrices: have only on row

EG. [7 5 3 2 9]

Column Matrices: have only one column

Eg.

[6]

[5]

[2]

[9]

[5]

Multiplication by a scalar:

To multiply a matrix by a scalar quantity, we simply multiply each elemt by the scalar.

Eg.

5 [1 2] = [5 10]

[3 4] [15 20]

REMEMBER: Rows go across, columns go up and down.

Non- Dictionary Stuff:

How to use your Graphing Calculator For matrix activities:

For TI-83:

Hit the Matrix Button,

Scroll across at the top of the screen to Edit,

Plug in the dimensions (# enter # Enter),

Plug in your elements,

Name your Matrix (A-J),

you can now do operations by going all the way to the left on the top of the screen.

Ex A + B will add matrix A and Matrix B,

to store a matrix, hit the store button.

you will get: ANS --> (designate an unused matrix)

Other things to know:

for this class, you should have 12 PENCILS! you may not hand in anything done in pen! keep two pencils in your binder, and ten more in your locker, YOU WILL NEED THEM THROUGH THE COURSE!

Commutative law: Basically, the statement that it matters in what order you subtract and divide numbers, but not what order you add and multiply.

We also learned about multiplying matrices, but that will be for tomorrows scribe as we have yet to take any dictionary notes.

Tomorrows scribe is: Jason

Posted by Nik # 1/2 | 2/07/2006 7:06 PM

## Post a Comment