Tuesday, 23 September 2014

reference request - Risch algorithm analogue for differential equations




I know that we can determine whether an integral has closed form, that is, is a composition of elementary functions. That problem is (more or less) solved by Risch algorithm. For differential equation solutions we consider a bit weaker condition, a solution can contain integrals of elementary functions.



Is there an algorithm which decides if solution can be expressed like that?


Answer



Yes. see this Wikipedia link (and some more characters to be on the safe side): https://www.wikiwand.com/en/Picard%E2%80%93Vessiot_theory


No comments:

Post a Comment

real analysis - How to find $lim_{hrightarrow 0}frac{sin(ha)}{h}$

How to find $\lim_{h\rightarrow 0}\frac{\sin(ha)}{h}$ without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...