What is "closed form"?
Q: What is "closed form"?
A: Suppose that you have two varibles x, y (similar for cases where you have more variables) and they are related by f(x, y) = 0. When it is possible to express x purely in terms of y, it is called closed form. For example, y^2 + sin(xy) = 0; You can find closed form solution for x in terms of y, but not y in terms of x.
--Ling Shi 5:44pm, 9 Oct 2006 (PDT)