numerical estimate of 2nd Order Diff Eq's in CAS

[Wes Loewer]

(11-15-2023 03:27 AM)Brian Zilli Wrote:  I don't know if this qualifies as built-in since it does require some pre-processing, but this is one way to do it:

Suppose we have a second-order equation x''=f(t,x,x'). If we let x0=x and x1=x', we may transform this into a system of first-order equations:

x0' = x1
x1' = f(t,x0,x1)

Thanks. As an educational exercise I wrote a little program that uses that idea with some Euler variations and RK4. It made me wonder if there might be something already built-in, perhaps undocumented.