Is there a way to do implicit differentiation on KhiCAS? Prototypical example:

I have dy/dx = x-y^2 and I would like KhiCAS to tell me that d^2y/dx^2 = 1-2y*(dy/dx).

diff(x-y(x)^2,x)
You will have to replace dy/dx by x-y^2 by hand.
implicitdiff in Xcas does more, but it's not yet in the Casio port.

I see. I managed to figure it out, thank you for your help. Furthermore, is it possible to compute the n'th derivative of a function? I know it is possible it returns an input if n itself is part of the function i.e diff(n*e^x, x, n) will work (incorrectly), but diff(e^(2x), x, n) (which should return (2^n)e^(2x)) will not. Is there a workaround where I possibly define n first?

It seems an inefficient, but still a working method is to use finite differences, see an explicit formula here: https://www.reddit.com/r/math/comments/1cv1ius/formula_for_the_nth_derivative/

Thanks!

N:=5; diff(exp(2x),x,N) will correctly return 32*exp(2*x), and this is also the case for every positive integer N that has a defined value.
It is not possible to compute the N-th derivative of a generic expression if N is symbolic. There are exceptions of course, exp(2x) is one of them, sin(x) would also, but it's only possible for very simple examples like that. Think of an expression like exp(sin(x)) or 1/(1+exp(x^2))
Finite differences methods can not be used to compute a symbolic derivative, only approximations (if all parameters have fixed values).