Let us now consider the issue of evaluating the term of Eq. (19.5), for a typical element
(20.7)
where and for the element. Thus, the conduction contribution of an element to the residual equation at a node takes the form of a 3 ×3 matrix multiplied by a 3×1 vector. Substituting for and one can obtain all the entries of the 3 ×3 matrix .
of Eq. (19.5), for a typical element 
and 
for the element. Thus, the conduction contribution of an element to the residual equation at a node takes the form of a 3 ×3 matrix 
multiplied by 
a 3×1 vector. Substituting for 
and 
one can obtain all the entries of the 3 ×3 matrix 
and 
and 
and 
