I seem to be having some trouble with scalar multiplication. Perhaps you all can help out. Here is what I have; with(LinearAlgebra): A:= matrix(3,3,[1,2,3,4,5,6,7,8,9]); ScalarMultiply(A,3); I was hoping that would work, but after the ScalarMultiply command I get "Error, (in LinearAlgebra:-ScalarMultiply) expects its 1st argument, MV, to be of type {Matrix,Vector}, but received A" Any ideas where I am going wrong? Thanks in advance.

I could use a hand with a problem our class has. we have the function xy+yz+zx=3 I would like to find a way to graph the surface, the tangent plane at the point (1,1,1) and the normal line all on the same graph. We have tried a couple different methods and have failed miserably. We are using Maple 10 Thanks in advance! Michael

I have the function f(x,y)=(x^2+3y^2)e^-x^(2)-y^(2), and when I try to graph it with either plot 3d or implicit plot 3d I get nothing. Ant ideas what I need to do? Thanks!