How to write a quadratic equation with positive or negative coefficients

How to write a quadratic equation with positive or negative coefficients

de către Dominique Bauer-
Număr de răspunsuri: 6
Fotografia lui Documentation writers Fotografia lui Particularly helpful Moodlers Fotografia lui Plugin developers

Since we often use equations in quizzes, I'm opening this discussion in the quiz forum.

Formulas_20200828_0017.png

The question looks like this:



Try it at https://moodleformulas.org/course/view.php?id=36&section=2 ↗

The way I describe above works fine. Does anyone know of an easier way to achieve the same result?

Media aprecierilor: -
Ca răspuns la Dominique Bauer

Re: How to write a quadratic equation with positive or negative coefficients

de către David Galiana-

Hi Dominique

There is a simpler way to write polynomials using Moodle Formulas: poly() function.

For instance: 

Global variables:

equation=poly("x",[2,-3-5]);

Question text: \\({equation}=0\\) will throw \(2x^2-3x-5=0\)

Sample question attached.
Media aprecierilor: -
Ca răspuns la David Galiana

Re: How to write a quadratic equation with positive or negative coefficients

de către Ton Boerkoel-
That is very cool, David! I had another work around---that I was proud of---but using the poly() function is brilliant.
Media aprecierilor: -
Ca răspuns la Ton Boerkoel

Re: How to write a quadratic equation with positive or negative coefficients

de către Ton Boerkoel-
There is still the issue when we have polynomial equations with more than one variable x, y z, in which case  poly()  doesn't quite work. Below I have a way (using just builtin functions) to produce nice results. 

For example we would like to write {a11}x+{a12}y+{a13}z nicer.e.g.








Here is the code that produces this


and


Of course you can also code this with Javascript, but, as you can see, it can be done with string operations too.










Media aprecierilor: -
Ca răspuns la Ton Boerkoel

Re: How to write a quadratic equation with positive or negative coefficients

de către Ton Boerkoel-
Here is a slightly improved version. The code maybe easier to read.
 


Media aprecierilor: -
Ca răspuns la David Galiana

Re: How to write a quadratic equation with positive or negative coefficients

de către Dominique Bauer-
Fotografia lui Documentation writers Fotografia lui Particularly helpful Moodlers Fotografia lui Plugin developers
Hello David,

Of course. What was I thinking!

Thank you for your post.
Media aprecierilor: -