VALUE OF A VARIABLE OF POLINOMIAL FUNCION

HI

sorry by the stupid question
but i need compute the following

i have a matrix A= x2*y1,y4, 3*x4,5;
this matrix represent a jacob matrix of a given poly

i have too values for get into this matrix to find a intmat

understand??

ex

|x 2x| ==> x= 3; ===> intmat = |3 6 |
|3x 4x|.............................|9 12|

how i can do it

thanks, and sorry my horryble english
i`m brazilian and dont speak very good

Hi,

no problem. Just use the substitution command "subst"; like this:

ring r = 0, (x,y,z), dp;
matrix A[2][2]=x2*y,y4,3*x4,5;
subst(A, x, 1, y, 0); // e.g., x = 1, y = 0
// yields this:
_[1,1]=0
_[1,2]=0
_[2,1]=3
_[2,2]=5

Regards,
Frank

THANKS