## Question types: Algebra

qtype_algebra

Maintained by Jean-Michel Védrine

Question type where the student must answer by typing an algebra formula. Correctness can be checked by three different methods.

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MOODLE ALGEBRA QUESTION TYPE

Created by Roger Moore

Algebra based question type for Moodle.

This plugin implements an algebraic question type where student responses are treated as an algebraic expression and compared to instructor provided answers using the basic rules of algebra.

### Sets

This plugin is part of set Seeking new maintainer.

### Useful links

### Contributors

Jean-Michel Védrine (Lead maintainer)

Roger Moore: Original Author

Please login to view contributors details and/or to contact them

I use the current version with Moodle 2.6 and also Moodle 2.7beta and I have not seen any problem. Also nobody reported any bug so I think you are safe to use it with Moodle 2.6. If you see any bug or problem, create a tracker issue and I will work on it.

we are using the algebra question type on a Moodle 2.9 server, but we have a problem with the formula preview: We cannot make the TeX preview work with MathJax. MathJax is enabled and works everywhere else on the site, but the preview in the algebra questions remains raw TeX code. If we enable the old TeX filter, the formulas get converted to images, but it also breaks the displayed formulas in the rest of the site: All TeX is interpreted as inline math.

Do you have any idea, what might cause this and how to fix it?

I solved my problem described above. To fix the LaTeX preview of the algebra questions, I had to insert the line

into the "Within HEAD" section in the "Site administration > Appearance > Additional HTML" settings. Now the preview uses MathJax as it should.

Cheers

Lukas

The line should read:

[script type="text/javascript" src="https://cdn.mathjax.org/mathjax/2.5-latest/MathJax.js?config=TeX-AMS_HTML"][/script]

Just replace the square brackets with the angular html kind.

Similarly to Lukas we are using the algebra question type on a Moodle 2.8 server, the TeX preview does not work with MathJax. MathJax is enabled and works everywhere else on the site, but the preview in the algebra questions remains raw TeX code. The fix Lukas mentions above cannot be implemented on our server, is there any alternative way of correcting this?

Thanking you in advance,

Janice

I have released a new version that should solve the problem with the display of the formula entered by the student.

I am not quite satisfied with the way I choose to solve this problem but that's all I can do for now.

I think it's honest to say that my teacher career will end in 5 months from now and I am not sure I will be able to maintain that plugin after that date.

Thanks for your great plugin! I sometimes get the following error displayed:

Notice: Undefined property: qtype_algebra_parser_bracket::$_sign in /path_to_moodle/question/type/algebra/parser.php on line 896 Notice: Undefined property: qtype_algebra_parser_bracket::$_sign in /path_to_moodle/question/type/algebra/parser.php on line 1339 Notice: Undefined property: qtype_algebra_parser_bracket::$_sign in /path_to_moodle/question/type/algebra/parser.php on line 896 Notice: Undefined property: qtype_algebra_parser_bracket::$_sign in /path_to_moodle/question/type/algebra/parser.php on line 1339

We use Moodle 3.0.2

Any suggestions?

Dear,

Berni

Since the upgrade to moodle 3,0 , we get the same error message as Bernhard Piazzi (above) so that most algebra questions won't work any more on our site:

As soon as there is a parenthesis in the answer of the student (example 8*(4x−3) ) we get this error message:

"Notice: Undefined property: qtype_algebra_parser_bracket::$_sign in /var/www/moodle-3.1.1plus/question/type/algebra/parser.php on line 896" (or sometimes "line 1339")

If somebody came accross this same problem and were able to solve it, could you please help me ?

We have no moodle developper on our site and without your help our hundreds of algebra questions are just going to get lost !

Many thanks in advance!

Sophie

a friend helped me with the above problem

(Notice: Undefined property: qtype_algebra_parser_bracket::$_sign in /var/www/moodle-3.1.1plus/question/type/algebra/parser.php on line 896" (or sometimes "line 1339"))

I'll try to translate the solution:

A variable was not initialized ($_sign) in the constructor of the class qtype_algebra_parser_bracket.

To correct this you have to modify the file : question/type/algebra/parser.php (line 1309) and add an initializing line :

function qtype_algebra_parser_bracket($text) {

parent::qtype_algebra_parser_term(self::NARGS,self::$formats[$text],$text);

$this->_sign=''; // line added

$this->_open=$text;

I hope it helps if you come accross the same problem.

Sophie