solve() problems

[HansB]

(06-07-2021 06:09 PM)C.Ret Wrote:  The good new is you don't need to program any reverse functionality:

The name of the slot F1 F2 ... F9 F0 are global , you can directly use they with CAS variables : F1(x) returns the initial expression !

All CAS functions and Twix are available.

Ahh, thank you! The small x again! solve(F1(x)) etc works great in CAS, but F1 imports the expression rather differently than F1(x), and F1(X) throws an error. Then in CAS the case of the alpha keys works opposite to that in Home, and opposite to what is written on the keys. All this needs getting used to by me, I need to watch the character case indicator top left like a hawk...

PS: I do find it a pity and somewhat a design flaw, that one cannot simply do in CAS for instance x^2-sqrt5+1—>F3 (but as textbook entry). Perhaps the Function app should have a modus for lower case x. Using your custom function CAS2FUN does not quite solve the problems, since an expression gets evaluated, like sqrt5 will be transformed into its numerical approximation.