Loading...

There was an error loading the page.


Try to answer the following questions here:

  • What is this question used for?
  • What does this question assess?
  • What does the student have to do?
  • How is the question randomised?
  • Are there any implementation details that editors should be aware of?

Metadata

Taxonomy:

History and Feedback

Comment

Checkpoint description

Describe what's changed since the last checkpoint.

Elliott Fletcher 2 years, 1 month ago

Published this.
Picture of Christian Lawson-Perfect

Christian Lawson-Perfect 2 years, 2 months ago

Gave some feedback: Ready to use

Picture of Christian Lawson-Perfect

Christian Lawson-Perfect 2 years, 2 months ago

Saved a checkpoint:

I've split the last part, which asked you to find solutions after completing the square, into a separate question.

I moved the "Write the following expression in the form ..." text into the statement, because it's repeated for every part.

The advice now begins with a concise description of completing the square, which means the advice for the individual parts can just show how it's done.

The marking uses string restrictions, which just about does the job - you'd have to give a pretty artifical answer to get away with not completing the square - but it would be better if it did pattern-matching.

Restore this checkpoint

Hannah Aldous 2 years, 2 months ago

Gave some feedback: Needs to be tested

Picture of Chris Graham

Chris Graham 2 years, 2 months ago

Gave some feedback: Has some problems

Picture of Chris Graham

Chris Graham 2 years, 2 months ago

You seem to have sorted the pattern matching and there is a nice gradient of difficulty now.

In the part prompts, replacing e.g. "the expression" with "the following expression" will be clearer to the student.

I would suggest that part (d) becomes its own question, and then you could split this into two parts: the first part completing the square and the second finding the solutions.

Hannah Aldous 2 years, 2 months ago

Gave some feedback: Needs to be tested

Lauren Richards 2 years, 2 months ago

  • Great question but some minor changes: 
  • Remember to full stop the end of your maths in each section of the advice. 
  • Your advice doesn't match the parts. The advice has writing for a)i), ii) and iii) but there are only questions i) and ii). There is also advice for b)i), ii) and iii) and yet only one question for b). 
    a)ii) shouldn't be in the advice - that does not correspond to any question. b)ii) and b)iii) shouldn't be there either. 
  • In d), the answer for x1 and x2 were switched around in the advice. The advice is the incorrect version. 
  • Check the working for c)i), I am not sure that it is correct but it does end up with the right answer. Where does the last term from the original expression go and where do the two numbers in the penultimate line appear from? Same for c)ii). 
  • part d) - is the square of the integer in the bracket supposed to be in the form 2^2 rather than 4? Everywhere else in the question it has been in the form 4. 

Lauren Richards 2 years, 2 months ago

Gave some feedback: Has some problems

Picture of Christian Lawson-Perfect

Christian Lawson-Perfect 2 years, 2 months ago

Gave some feedback: Has some problems

Picture of Christian Lawson-Perfect

Christian Lawson-Perfect 2 years, 2 months ago

Saved a checkpoint:

Why are there three of each type of equation? Unless there's some kind of development, you should have one of each instance; the student can retry the question to get more examples.

The marking doesn't check that the student has put the expressions in the desired form. Ask Elliott about pattern-matching.

You could scale things so that only integers are used in the answer to part d. (I got $0.5 \pm \sqrt{50.25}$)

Restore this checkpoint

Hannah Aldous 2 years, 2 months ago

Gave some feedback: Needs to be tested

Elliott Fletcher 2 years, 2 months ago

Gave some feedback: Has some problems

Elliott Fletcher 2 years, 2 months ago

Main Parts

a) good

b) i) and ii) good

b) iii) I think there is an error here, i got $\simplify{x^2+29x-7}$, so i calculated the correct answer as (x+29/2)^2-869/4, however the displayed correct answer is (x+29/2)^2-71.

c) i) I think there is an error here, i got $\simplify{6x^2+36x+13}$, so i got the answer as 6(x+3)^2-41. The advice section also shows this answer, but the displayed answer 6(x+3)^2-51.

c) ii) There is an error here too, i got $\simplify{3x^2+60x-10}$, so i think the answer should be 3(x+10)^2-310, but the displayed answer is 3(x+10)^2-59.

d) good, but i would relabel the two possible answers here, as you have in the advice section as x1 and x2 (x1 being the smaller one).

Advice

I think it's fine if you don't show the working out for every question (because i know how long that would take), but i think you should say at the beginning of the advice for each part something like "We will just do one question from each part, as the other questions follow the same pattern" or "This can be similarly done for ii) and iii)".

d) I would write the numbers as fractions instead of decimals, so it's easier for the students to follow. Also, you say in the question to give the smallest answer first, so i think x1 should be the smaller number instead of x2.

Hannah Aldous 2 years, 2 months ago

Gave some feedback: Needs to be tested

Vicky Hall 2 years, 2 months ago

Gave some feedback: Has some problems

Vicky Hall 2 years, 2 months ago

In all parts of the question, put $\=$ after the expression and before the answer box.

In the advice, make sure a), b) etc are in heading 4 and that your solutions begin on the next line down. Anywhere that you reference an earlier part, write it as a) rather than a. You should write solutions for all subparts, although I agree that only subpart i) needs to go into detail. 

In part d) of the advice, make sure that when you take the square root you find $\pm$ answer, which you can do by using \pm. The last lines of this section aren't rendering so have a look at that.

When I tried part c), the solution in the advice came up with a recurring decimal, although this only happens some of the time. I'd fix this so that Numbas produces a fraction instead, which should happen if you use the \simplify command. 

Also ensure all of your equations in the advice display in the centre of the screen.

Hannah Aldous 2 years, 3 months ago

Gave some feedback: Needs to be tested

Hannah Aldous 2 years, 3 months ago

Created this.
Name Status Author Last Modified
Completing the square Ready to use Hannah Aldous 01/08/2017 14:08
Complete the square and find solutions Ready to use Christian Lawson-Perfect 13/08/2019 16:36
Inbbavathie's copy of Complete the square and find solutions (SP1) draft Inbbavathie Ravi 15/07/2017 22:57
Inbbavathie's copy of Complete the square and find solutions draft Inbbavathie Ravi 24/07/2017 03:48
Katherine's copy of Complete the square and find solutions draft Katherine Tomlinson 02/08/2017 12:47
Complete the square and find solutions [L4 Randomised] Needs to be tested Matthew James Sykes 25/07/2018 10:17
Ann's copy of Complete the square and find solutions draft Ann Smith 09/10/2018 12:27
Completing the square draft Adrian Jannetta 22/10/2018 08:05
Complete the square and find solutions draft Johnny Yi 30/04/2019 05:46
Simon's copy of Completing the square draft Simon Thomas 07/03/2019 10:08
Simon's copy of Complete the square and find solutions draft Simon Thomas 07/03/2019 10:10
JD's copy of Completing the square draft JD Ichwan 21/05/2019 05:37
Completing the square and finding roots of a quadratic equation draft Maria Pickett 11/09/2019 13:51
Paul's copy of Complete the square and find solutions draft Paul Verheyen 05/09/2019 12:59
F11MTC - Topic 3 - Completing the Square draft Oscar Siles Brugge 11/09/2019 14:20

Give any introductory information the student needs.

No variables have been defined in this question.

(a number)

Numbers between and (inclusive) with step size
A random number between and (inclusive) with step size

(text string)

(numbers)

(text strings)

This variable is an HTML node. HTML nodes can not be relied upon to work correctly when resuming a session - for example, attached event callbacks will be lost, and mathematical notation will likely also break.

If this causes problems, try to create HTML nodes where you use them in content areas, instead of storing them in variables.

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

Name Type Generated Value

Error in variable testing condition

There's an error in the condition you specified in the Variable testing tab. Variable values can't be generated until it's fixed.

Error:

for seconds

Running for ...

No parts have been defined in this question.

Select a part to edit.

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

The correct answer is an equation. Use the accuracy tab to generate variable values satisfying this equation so it can be marked accurately.

Advanced settings


Checking accuracy

Define the range of points over which the student's answer will be compared with the correct answer, and the method used to compare them.

Variable value generators

Give expressions which produce values for each of the variables in the expected answer. Leave blank to pick a random value from the range defined above, following the inferred type of the variable.

Pattern restriction


Variables


String restrictions

Advanced settings




Advanced settings


Advanced settings



Advanced settings



Advanced settings



Answers
Choices
Both choices and answers must be defined for this part.

Advanced settings




Help with this part type


Base marking algorithm

                                        
Custom marking algorithm


Test that the marking algorithm works

Check that the marking algorithm works with different sets of variables and student answers using the interface below.

Create unit tests to save expected results and to document how the algorithm should work.

There's an error which means the marking algorithm can't run:


                                    
Name Value

Note
Value Feedback

Click on a note's name to show or hide it. Only shown notes will be included when you create a unit test.


Unit tests

No unit tests have been defined. Enter an answer above, select one or more notes, and click the "Create a unit test" button.

The following tests check that the question is behaving as desired.

This test has not been run yet This test produces the expected output This test does not produce the expected output

This test is not currently producing the expected result. Fix the marking algorithm to produce the expected results detailed below or, if this test is out of date, update the test to accept the current values.

One or more notes in this test are no longer defined. If these notes are no longer needed, you should delete this test.

Name Value

Note Value Feedback
This note produces the expected output Current:
Expected:

This test has not yet been run.

When you need to change the way this part works beyond the available options, you can write JavaScript code to be executed at the times described below.

Run this script the built-in script.

This script runs after the built-in script.

To account for errors made by the student in earlier calculations, replace question variables with answers to earlier parts.

In order to create a variable replacement, you must define at least one variable and one other part.

Variable Answer to use Must be answered?

The variable replacements you've chosen will cause the following variables to be regenerated each time the student submits an answer to this part:

These variables have some random elements, which means they're not guaranteed to have the same value each time the student submits an answer. You should define new variables to store the random elements, so that they remain the same each time this part is marked.

More information about this problem

to

Parts

Give a worked solution to the whole question.

Extensions

Rulesets

Functions

Preamble

This script will run after the question's variable have been generated but before the HTML is attached.
Apply styling rules to the question's content.

This question is used in the following exams: