(48G 49G 50G) Runge-Kutta Diff Eqn solver

[rcthacker]

"Instead of an equation for F, the calculator also accepts a program, so all we need to do is write one that will return [ v g-k*v^2 ] from U = [ y v ]" This isn't in any documentation I've seen. Where did you find it?

This works fine from num.slv.

What would you do if invoking from the program function RKF? I tried it, but it wouldn't accept the program inlieu of a function.