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Can higher order derivatives be obtained in CAS, (without programming)?

Example:
z:=(3*x^2-y^2) = 16,
simplify(implicit_diff(z,x,y))
leads to 3*x /y as the first derivative of z.

How would one obtain the (Second derivative): d^2y/dx^2=(3*y-3*x*3*x/y)/y^2 (or simplified equivalent)?

-Dale-
simplify(implicit_diff(z,x,y,2)) works for me on the latest version. So next update (if any) should have it being very simple at least.
Thank you kind sir. (I should have thought to try that!)
-Dale-
I have tried that on my Prime with software 2017 07 10 (12066) and cas 1.1.2-11
and the command implicit_diff(z,x,y,2) gace Error Bad Argument Value
Yes, we mere mortals will have to wait for the next firmware update (if any!) . . . maybe more XCAS commands will be implemented as well, as discussed here

http://www.hpmuseum.org/forum/thread-857...light=xcas
In the meantime, you can enter this program:
Code:
``` idiff(eq,x,y,n):=begin   local j,dn,d1;   d1:=-diff(eq,x)/diff(eq,y);   dn:=d1;   for j from 2 to n do     dn:=diff(dn,x)+diff(dn,y)*d1;   end;   return dn; end```
Great! Just two minor modifications. In order to run on the Prime current firmware,

1) n=1 in the first line gives an error message "unable to eval test in loop . . . " and ought to be replaced by n

2) eq should not be entered as an equation, but as an expression, in order to avoid the =undef
I have edited the n=1 (default argument not available in current firmware).
Reference URL's
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