Save functions for later use?



Hi,

As an old Mathcad user I'm used to save some of my most used formulas
as a worksheet. Is there some similar functionality in Maxima?
Basically, when I've defined a function, is it possible to save that
function somewhere, close maxima, open it again, and use that
function?

I quite often use the Quadratic Formula at school and it's really a
pain to re-type it almost every day.

Besides that, Maxima is a really great piece of work!

-- 
Sincerely,

Dan Sondergaard