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Roberta Bloom - Mathematics

Math 11 Chapter 2 Matrices

Chapter 2 Homework and Resources

Section 2.1 :
Do problems 1 thru 5, 7, 10, 11, 14-19, 21

Section 2.2 :
Solve using Gauss Jordan Method: 4x + 12y = 52 , 2x + y = −9
Do problems 1-4 in textbook

Some Video Examples using Row Operations with the Gauss Jordan Method of Elimination to get Reduced Row Echelon form.  Video links on You-Tube will open in a new window or tab in the browser.

This  video shows a system of 2 equations and 2 variables. The instructor in the video writes a lot more of the arithmetic work on her paper, but she is doing the same process.  The arithmetic is a little harder (some fractions)  than the examples I did in class.

This video also shows a system of 2 equations and 2 variables.

This video shows a system of 3 equations and 3 variables.

To check your answers in Section 2.2 you can:
a) substitute your answers into the equations and check if your answers satisfy all the equations OR
b) go to Wolfram Alpha and select the window for solving a system of linear equations or go directly to 
Input your equations to get the answer.
Wolfram Alpha will give you answers for free,but not worked out solutions
c) put the augmented matrix into your calculator using 2nd MATRIX EDIT
Use 2nd MATRIX MATH B:rref with your matrix name from the MATRIX menu to get the answer. You will be required to show work written out using the requested method(s) on quizzes or exams, but you can use this on your calculator to check your solution.

Your calculator has built in row operation functions for Matrices
I think its harder to do using the calculator than by hand, since I usually make questions with fairly easy arithmetic for exams and quizzes.
I find it hard to remember how to use the row operation commands correctly as you need to put the input in exactly correctly in the right order or the calculator will do the wrong thing.
If you want instructions, here is a video from the Learning Assistance Center at Howard Community College.
I will not teach this calculator method because I think its easier and faster to do by hand.
If you want to learn the calculator commands from this video, you can use this method on the calculator for homework, tests and quizzes.  But I can not help you with this on the calcululator

Section 2.3 :
Do problems 1, 3, 5, 8, 9
Also do review problems 8a, 8b from section 2.7

Section 2.4
Do problems 1, 3, 4, 5, 7, 8, 9, 10
Note: Problem 7 uses A-1 from problem 3
Problem 8 uses A-1 from problem 4
Problem 9 uses A-1 from problem 5
Problem 10 uses A-1 from problem 6, which was not assigned, so just use the calculator to find A-1 using the x-1 inverse key.

email icon Email: Roberta Bloom
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Last Updated: 10/5/17