10.2 Day 3 Systems of Linear Equations - Matrices 2010

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10.2 Day 3 Systems of Linear Equations Matrices 2010 1 December 08, 2010 Nov 912:20 PM 10.2 Systems of Linear Equations: Matrices Day 3 Objectives: 1. Write the augmented matrix of a system of linear equations. 2. Write the system from the augmented matrix. 3. Perform row operations on a matrix. 4. Solve a system of linear equations using matrices.

Transcript of 10.2 Day 3 Systems of Linear Equations - Matrices 2010

Page 1: 10.2 Day 3 Systems of Linear Equations - Matrices 2010

10.2 Day 3 Systems of Linear Equations ­ Matrices 2010 

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December 08, 2010

Nov 9­12:20 PM

10.2 Systems of Linear Equations: Matrices 

Day 3

Objectives:1. Write the augmented matrix of a system of linear equations. 2. Write the system from the augmented matrix.3. Perform row operations on a matrix.4. Solve a system of linear equations using matrices. 

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December 08, 2010

Dec 6­12:13 PM

1.     2.

Warm­up:Given reduced row echelon form write the system of equations corresponding to the given matrix.  Is the system consistent or inconsistent?  If consistent, give the solution.

[    ]1     0     0      ­80     1     0       50     0     1       0 [    ]1     0    ­3       4

0     1     2       70     0     0       0

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December 08, 2010

Dec 8­12:27 PM

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December 08, 2010

Nov 30­12:40 PM

Ready?...time to put it 

all together!!

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December 08, 2010

Nov 30­12:40 PM

Solve a System of Linear Equations Using Matrices 

{2x + 2y       = 6 x  +  y  + z = 13x + 4y  ­ z = 13

Example #1:  Solve the system of equations using matrices (row operations).  If the system has no solution, say that it is inconsistent.

Step 1:  Write the system as an augmented matrix.

Step 2:  Use row operations to change into row echelon form.  HINT:  Start with the first column.

Step 3:  Solve for each variable.

x = 1, y = 2, z = ­2Answer:

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December 08, 2010

Nov 30­12:40 PM

Solve a System of Linear Equations Using Matrices Example #2:  Solve the system of equations using matrices (row operations).  If the system has no solution, say that it is inconsistent.

4x ­ 3y  + 5z = 02x + 4y  ­ 3z = 06x + 2y  +  z = 0

{

x = ­      z,  y = z,  z = any real numberAnswer: 12

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December 08, 2010

Nov 30­12:40 PM

Solve a System of Linear Equations Using Matrices Example #3:  Solve the system of equations using matrices (row operations).  If the system has no solution, say that it is inconsistent.

{ x  +   y  +  z  = 62x  ­   y  ­   z  = 3 x  + 2y  + 2z = 0

InconsistentAnswer:

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December 08, 2010

Nov 30­12:40 PM

Homework: page 754 (37 ­ 59 odd)