In a pg-file, I defined the following variable that stores the answer to a question:
$xAnti = FormulaUpToConstant("(-1/15)*e^(-5*x^3)");
I am using the default answer checker (via PGML syntax)
The problem is that the student's correct answer is not being registered as correct. This seems to only happen with this combination of constants. For example, if I change the -5 to a -4, it works as expected.
HOWEVER, if I also simply change the order of the multiplication to
$xAnti = FormulaUpToConstant("e^(-5*x^3)/-15");
the problem works fine.
Does anyone know why this would happen?