Derivatives

[robmio]

(10-02-2022 12:47 AM)Eddie W. Shore Wrote:  Trying the second derivative in a program:

Code:

EXPORT DER2(f,v,n)
BEGIN
LOCAL d;
d:=diff(f,v,2,v=n);
RETURN d;
END;

Home:
DER2(X^3,X,1) -> Error: Bad argument value ("diff(f,v,2,v=n)")]
DER2('X^3','X',1) -> diff(diff(3.006003,2),0)

CAS:
DER2(X^3,X,1) -> Error: Bad argument value ("diff(f,v,2,v=n)")]
DER2(x^3,x,1) -> diff(diff(3*x^2,2),0)

I hope that the next Prime update will allow for numerical differentiation for both first and second derivatives.

Hello, try using this little program:

Code:


#cas
DER2(funz,grado,num):=
BEGIN
LOCAL dd, vrb, risultato;
vrb:=lname(funz);
vrb:=vrb(1);
dd:=diff(funz,vrb,grado);
risultato:=subst(dd,vrb=num);
RETURN risultato;
END;
#end

Example:
DER2 (function, degree of derivation, number)
DER (t ^ 3,2,4) -> 24

Sincerely, robmio