Degree of a Polynomial (x, y, z, t) (CAS)

[Eddie W. Shore]

The program degpoly is a more complete version of the degree command. The degree command tests a single variable, default to x if no variable is specified. The program degpoly calculates the degree of a polynomial, considering four variables: x, y, z, and t. Combinations of these four variables, such as x*y, x*y*z, and t*z are also considered.

HP Program degpoly:

Code:

#cas
degpoly(poly):=
BEGIN
// 2016-07-31 EWS
// x,y,z,t
LOCAL tms,cnt,pt,lst,wp,dg,dgr;
tms:=part(poly);
lst:={};

FOR pt FROM 1 TO tms DO
wp:=part(poly,pt);
dg:=degree(wp,x)+degree(wp,y)+
degree(wp,z)+degree(wp,t);
lst:=concat(lst,{dg});
END;

dgr:=MAX(lst);
return dgr;
END;
#end

I recommend that you type out the commands when programming in CAS mode. Make sure the suffix “CAS.” is removed from any command inside the program.

Accessing CAS Programs

In CAS mode, press [Vars], then the soft key (CAS), select Program for the list of programs

Examples:
degpoly(x^2 + 3*x – 1) returns 2
degpoly(x^2 + 3*y – 1) returns 2
degpoly(x*y – y^2 + t) returns 2
degpoly(x^2*y^2 – 3*z^2) returns 4