Problems with commas and functions of two variables

[nielsle]

Hi Michael

I have some problems with using comma as argument separator when calculating partial derivatives of functions of two variables in wordmat. Here is an example

f(x,y):=x^2+y^2
f_x'(x, y) = 2*x
f_x'(2, 3) = 4,6   // I had expected either 2*2=4 or an error

Attached example file in Danish
funktioner_af_to_variable_i_wordmat.docx

Kind regards
Niels

[Eduap-com]

Thank you. I will have a look at it.

[Eduap-com]

The problem is that WordMat sees 2,3 as the number 2,3 and not two different numbers 2 and 3. Hence x=2,3.
This can be resolved by putting a space after the comma 2, 3 (as you do in the text above, but not in the Word document) as WordMat then recognized this as two numbers and internally replaces , y ;
Thanks for attaching the docx file making it easy to resolve.
I can see that this could potentially throw students off, and it would be better with an error, but I am not sure how to change this as it depends on Maxima behavior.

[nielsle]

Thank you for the quick response. I was mostly worried about the following line

f(x, y) := x^2+y^2
f_x'(2,3) =4,6   // because 2*2.3=4.6

As I see it f_x'(x,y) is function of two variables, so if wordmat interprets 2,3 as a Danish decimal number, then I would prefer wordmat to fail with a warning saying

Too few arguments