Matrix times vector (same as WBQ 1.27)

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Julia Goedecke

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Julia Goedecke

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Ready to use

4 years, 6 months ago

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Julia Goedecke 4 years, 6 months ago

Gave some feedback: Ready to use

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Julia Goedecke 4 years, 7 months ago

Gave some feedback: Needs to be tested

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Julia Goedecke 4 years, 7 months ago

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Julia Goedecke 4 years, 7 months ago

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Name	Status	Author	Last Modified
Matrix times vector (same as WBQ 1.27)	Ready to use	Julia Goedecke	25/08/2021 12:57
Matrix times vector (WBQ 1.27 randomized)	Ready to use	Julia Goedecke	25/08/2021 12:57
copy of Matrix times vector	Ready to use	Julia Goedecke	25/08/2021 12:57
copy of Matrix times vector (WBQ 1.27 randomized)	Ready to use	Julia Goedecke	25/08/2021 12:57

There are 8 other versions that do you not have access to.

Question statement

Calculate the following:

(This question is not randomized: it is the same as our Workbook Question 1.27. You can find a randomized version of it as well.)

Give any introductory information the student needs.

			Name	Type	Generated Value

A	matrix	matrix([3,2],[5,1])
va	vector	vector(1,1)
B	matrix	matrix([1,3,2],[9,2,-1])
vb	vector	vector(1,3,2)
C	matrix	Matrix of size 3×3
vc	vector	vector(1,2,3)
D	matrix	matrix([1,9],[2,3],[2,-1])
vd	vector	vector(-1,2)
rawunresolvedAva	list	List of 4 items
unresolvedAva	string	\begin{pmatrix}3\cdot1+2\cdot1
rawunresolvedBvb	list	List of 6 items
unresolvedBvb	string	\begin{pmatrix}1\cdot1+3\cdot3
rawunresolvedCvC	list	List of 9 items
unresolvedCvc	string	\begin{pmatrix}1\cdot1+9\cdot2
rawunresolvedDvd	list	List of 6 items
unresolvedDvd	string	\begin{pmatrix}1\cdot(-1)+9\cd

Automatically regenerate variables?

Name

Data type

Value

xxxxxxxxxx
 
matrix([3,2],[5,1])

JME function reference

Description

Describe what this variable represents, and list any assumptions made about its value.

Can an exam override the value of this variable?

Generated value: `matrix`

matrix([3,2],[5,1])

→ Used by:

rawunresolvedAva

Advice
"Part a)" - prompt
"Part a)" → "Unnamed gap" - Correct answer

Parts

Part a) Gap-fill
1. Gap Matrix entry
  Add
Part b) Gap-fill
1. Gap Matrix entry
  Add
Part c) Gap-fill
1. Gap Matrix entry
  Add
Part d) Gap-fill
1. Gap Matrix entry
  Add

Gap-fill

Ask the student a question, and give any hints about how they should answer this part.

$\var{A}\var{va}=$ Unnamed gap

Advice

To calculate matrix times vector, we calculate this row by row: the first entry of the resulting vector is "row 1 of the matrix times the vector". For example

$\begin{pmatrix} a_{11} & a_{12} \\ a_{21} & a_{22}\end{pmatrix} \begin{pmatrix}x_1\\x_2\end{pmatrix}= \begin{pmatrix} a_{11}x_1+a_{12}x_2 \\ a_{21}x_1+a_{22}x_2\end{pmatrix}$

a) $\var{A}\var{va}=\var{unresolvedAva}=\var{A*va}$

b) $\var{B}\var{vb}=\var{unresolvedBvb}=\var{B*vb}$

c) $\var{C}\var{vc}=\var{unresolvedCvc}=\var{C*vc}$

d) $\var{D}\var{vd}=\var{unresolvedDvd}=\var{D*vd}$

Give a worked solution to the whole question.

Use this tab to check that this question works as expected.

There was an error which means the tests can't run:

Part	Test	Passed?
Gap-fill
Gap-fill		Hasn't run yet
Matrix entry
Matrix entry		Hasn't run yet
Gap-fill
Gap-fill		Hasn't run yet
Matrix entry
Matrix entry		Hasn't run yet
Gap-fill
Gap-fill		Hasn't run yet
Matrix entry
Matrix entry		Hasn't run yet
Gap-fill
Gap-fill		Hasn't run yet
Matrix entry
Matrix entry		Hasn't run yet

This question is used in the following exam:

Matrix times vector and matrix transformations by Julia Goedecke in Linear Algebra 1st year.

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Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

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Checkpoint description

Julia Goedecke 4 years, 6 months ago

Julia Goedecke 4 years, 7 months ago

Julia Goedecke 4 years, 7 months ago

Julia Goedecke 4 years, 7 months ago

Error in variable testing condition

Error

Warning

Generated value: `matrix`

Parts

Gap-fill

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Matrix times vector (same as WBQ 1.27)

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

Julia Goedecke 4 years, 6 months ago

Julia Goedecke 4 years, 7 months ago

Julia Goedecke 4 years, 7 months ago

Julia Goedecke 4 years, 7 months ago

Error in variable testing condition

Error

Warning

Generated value: matrix

Parts

Gap-fill

Generated value: `matrix`