# [LON-CAPA-users] formula response with cas

**H.K. Ng
**
lon-capa-users@mail.lon-capa.org

*Tue, 21 Oct 2008 15:09:52 -0400*

Hi,
I am writing some formula response problems and would like to use
maxima to compare two algebraic expressions. Basically, the questions
will ask the students to solve the problems algebraically and then
enter the expression. Some questions:
1. What is the maxima function to use in this case? Using Peter's
writeup, ratsimp works but does not seem appropriate when it is a
comparison of two expressions.
2. Also, reading Peter's writeup, it says that the expression is
passed to &implicit_multiplication function so that it inserts the
"*" symbol where a multiplication is implied. However, when I enter
v^2+2g(a-b) it is not graded correctly. On the other hand
v^2+2*g*(a-b) is graded correctly. What I am missing here?
3. How do I use greek symbols for an expression, both in the coded
answers and as input in the answer box? Drag math does insert greek
symbols but there doesn't seem to be a way to directly type it in?
Thanks,
-hk