Hints can be provided to students, based on the last response given, as well as the history of responses given. Here is an example of a hint produced by a Formula Response problem.
+ ++What is the equation of the line which passess through ($x1,$y1) and +($x2,$y2)?
+ +The correct answer is $answer. A common error is to invert the equation for the slope. Enter +$wrongans to see a hint.
+ ++A symbolic math response problem presents one or more symbolic math +input fields for input. Correctness of input is evaluated based on +the symbolic properties of the expression entered. The student enters +text, but sees a proper symbolic rendition of the entered formula, in +real time, next to the input box. +
+ +This is a correct answer which may be entered below:
+cos(theta)*[[1,0],[0,1]] + i*sin(theta)*[[0,1],[1,0]]
+ +