How complicated? Square roots? Cube roots? Logs? Exponentials? Differentials? Matrixes? Partial derivatives? And should it concern some particular subject? Do you need a numerical answer, or are variables in the solution okay? Multiple variables?

Just how messy do you want the equation to look, and just how messy can the answer be?

Paul

When in doubt, think about penguins. It probably won't help, but at least it'll be fun.