That particular matrix is based on a model published in a peer-reviewed journal, and it has both a trivial and nontrivial answer. But I really can't understand why my method isn't working. "LinearAlgebra[MatrixVectorMultiply](L,x)" gives a colum vector with 2 elements. And x has also two elements. It should be fairly simple to solve x=LinearAlgebra[MatrixVectorMultiply](L,x), I should be able to solve this by simultanously solving; x[1]=LinearAlgebra[MatrixVectorMultiply](L,x)[1] and x[2]=LinearAlgebra[MatrixVectorMultiply](L,x)[2] So; solve({x[1]=LinearAlgebra[MatrixVectorMultiply](L,x)[1],x[2]=LinearAlgebra[MatrixVectorMultiply](L,x)[2]},[x[1],x[2]]) But for some reason, it doesn't work. And thx you very much for the help.

Hi Your method only gives me an empty matrix... But anyway I think there's another way to do this. The equation for my matrix is; L:= Matrix([[s[1]*exp((x[1]+x[2])/K)(1-1/a),F],[s[1]*exp((x[1]+x[2])/K)*1/a,s[2]]]); Then I define my vector; x:=Vector([xj,xa]); The equation I want to solve is then; x=LinearAlgebra[MatrixVectorMultiply](L,x); which mean that I should be able to solve this simply with; solve({xj=LinearAlgebra[MatrixVectorMultiply](L,x)[1],xa=LinearAlgebra[MatrixVectorMultiply](L,x)[2]}, [xj, xa]); But for some reason I only get; "Warning, solutions may have been lost"

But, minimum or not, it doesn't matter. I need to know the value of the gradients; exp(x*y*z)*cos(x*y^3*z^2) and exp(x*y)*cos(x*y^3*z^2) at (0,0,0) And I want to know if Maple can solve this.