Mathematica and Matrices (From sci.math.symbolic)

*To*: mathgroup*Subject*: Mathematica and Matrices (From sci.math.symbolic)*From*: stevec (Steve Christensen)*Date*: Mon, 20 Mar 89 13:49:01 CST

gmk Mathematica and matrices 9:25 pm Mar 16, 1989(at wjh12.harvard.edu) (From News system) I have a Mathematica question. I did the following: In[1]:= y x . b - E[x . b] x.b Out[1]:= -E + yx.b In[2]:= D[%,b] x.b Out[2]:= -(E (0.b + x.1)) + y(0.b + x.1) Of course, this answer is right, but I would prefer if Mathematica knew that 0.b=0 and x.1=1, so that the above equation would be written as follows: x.b -x E + yx Does anyone know how to get Mathematica to do this? Thanks in advance Gary King ........... : Gary King, Department of Government, Harvard University, Cambridge, MA 02138 harvard.edu, BITnet: gmk at harvunxw, Phone: 617-495-2027