Assignment 15

course mth164

There are 2 submissions before this one. I kept hitting enter instead of tab to go to the next box by mistake. Sorry.

No problem.

?~???????p??V?assignment #015

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

015.

Precalculus II

07-17-2007

......!!!!!!!!...................................

08:14:38

Query 10.4.20 (5th ed 10.3.20) solve using determinants -x + 2y = 5, 4x - 8y = 6.

......!!!!!!!!...................................

RESPONSE -->

confidence assessment:

.................................................

......!!!!!!!!...................................

08:18:20

What is your solution?

......!!!!!!!!...................................

RESPONSE -->

The determinant is zero

The lines are parallel so there is no solution

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:20:10

Give the rows, one at a time (i.e., Enter between rows), for the determinant in the numerator of your solution for y, and give the determinant.

......!!!!!!!!...................................

RESPONSE -->

-1 5

4 6

determinant = -26

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:20:37

Give the rows, one at a time (i.e., Enter between rows), for the determinant in the denominator of your solution for y, and give the determinant.

......!!!!!!!!...................................

RESPONSE -->

-1 2

4 -8

determinant = 0

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:21:41

Query 10.4.30 (5th ed 10.3.30) solve using determinants x - y + z = -4, 2x - 3y + 4z = -15, 5x + y - 2z = 12.

......!!!!!!!!...................................

RESPONSE -->

confidence assessment:

.................................................

......!!!!!!!!...................................

08:22:28

What is your solution?

......!!!!!!!!...................................

RESPONSE -->

(1, 3, - 2)

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:24:02

Give the rows, one at a time (i.e., Enter between rows), for the determinant in the numerator of your solution for z, and give the determinant.

......!!!!!!!!...................................

RESPONSE -->

1 -1 -4

2 -3 -15

5 1 12

Determinant = 10

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:26:55

Explain in detail how you evaluated to determinant.

......!!!!!!!!...................................

RESPONSE -->

1 * determinant [[-3,-15],[1,12]] - (-1) * det [[2,-15],[5,12]] + (-4)*det[[2,-3],[5,1]]

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:27:43

Give the rows, one at a time (i.e., Enter between rows), for the determinant in the denominator of your solution for z, and give the determinant.

......!!!!!!!!...................................

RESPONSE -->

1 -1 1

2 -3 4

5 1 -2

det=-5

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:28:31

Query 10.5.6 (5th ed 10.4.6) A = [ [ 0,3,-5], [1,2,6] ]; B = [ [4,1,0], [-2,3,-2] ], C = [ [4,1], [6,2], [-2,3] ].

......!!!!!!!!...................................

RESPONSE -->

confidence assessment:

.................................................

......!!!!!!!!...................................

08:30:34

What did you obtain for the expression 2A + 4B?

......!!!!!!!!...................................

RESPONSE -->

2[[0,3,-5],[1,2,6]] + 4[[4,1,0],[-2,3,-2]]=

[[16, 10, -10],[-6, 16, 4]]

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:30:59

Query 10.5.10 (5th ed 10.4.10) A = [ [ 0,3,-5], [1,2,6] ]; B = [ [4,1,0], [-2,3,-2] ], C = [ [4,1], [6,2], [-2,3] ].

......!!!!!!!!...................................

RESPONSE -->

confidence assessment:

.................................................

......!!!!!!!!...................................

08:31:44

What did you obtain for the expression CB?

......!!!!!!!!...................................

RESPONSE -->

[[14, 7, -2],[20, 12, -4],[-14, 7, -6]]

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:31:58

Query 10.5.12 (5th ed 10.4.12) A = [ [ 0,3,-5], [1,2,6] ]; B = [ [4,1,0], [-2,3,-2] ], C = [ [4,1], [6,2], [-2,3] ].

......!!!!!!!!...................................

RESPONSE -->

confidence assessment:

.................................................

......!!!!!!!!...................................

08:33:43

What did you obtain for the expression C(A+B)?

......!!!!!!!!...................................

RESPONSE -->

I added the two matrices together first then multiplied by matrix C and got

[[15, 21, -16],[22, 34, -22],[-11, 7, 22]]

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:34:30

Query 10.5.44 (5th ed 10.4.44) solve using inverse matrix x + 2z = 6, -x + 2y + 3z = -5, x - y = 6.

......!!!!!!!!...................................

RESPONSE -->

confidence assessment:

.................................................

......!!!!!!!!...................................

08:35:11

What is your solution?

......!!!!!!!!...................................

RESPONSE -->

(4, -2, 1)

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:36:05

What is your inverse matrix?

......!!!!!!!!...................................

RESPONSE -->

[[3, -2, -4],[3, -2, -5],[-1, 1, 2]]

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:36:42

Give the rows, one at a time (i.e., Enter after each row), of the matrix you reduced to obtain the inverse.

......!!!!!!!!...................................

RESPONSE -->

1 0 2

-1 2 3

1 -1 0

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:58:17

Give the series of row operations you used to obtain your inverse matrix.

......!!!!!!!!...................................

RESPONSE -->

r1+r2 =r2

r3-r1=r3

gives

1 0 2 | 1 0 0

0 2 5 | 1 1 0

0 -1 -2 | -1 0 1

2r3+r2=r3

1 0 2 | 1 0 0

0 2 5 | 1 1 0

0 0 1 | -1 1 2

-2r3+r1=r1

-5r3+r2=r2

1 0 0 | 3 -2 -4

0 2 0 | 6 -4 -10

0 0 1 | -1 1 2

r2/2=r2

1 0 0 | 3 -2 -4

0 1 0 | 3 -2 -5

0 0 1 | -1 1 2

confidence assessment: 3

.................................................

......!!!!!!!!...................................

08:58:48

Comm on any surprises or insights you experienced as a result of this assignment.

......!!!!!!!!...................................

RESPONSE -->

Finding the inverse can be tedious and it is so easy to make a mistake since there can be so many row operations to make.

confidence assessment:

................................................."

Assignment 15

No problem.

&#

Very good responses. Let me know if you have questions. &#