I have an expression input where I ask students to give the equation of a line with a gradient of 3.
In order to ascertain correctness, I have code like this:
myLine = xyLine(exp.latex)
correct: myLine.slope = 3
The problem is that if a user types in “3x” then this will be marked as correct but really I don’t want to accept this.
Is there a way I could test to see if something was a well formed equation (or at least whether there was an equals sign in the string)?
I know I can also include initialLatex: "y = " but it still irks me that a student could take 3x, and perhaps Ialso want them to be able to enter in a different form like y - 3x = 10