with(LinearAlgebra):
A:=Matrix([[2,1,1],[1,2,1],[1,1,2]]);#A:=Matrix([[-1,1,3],[-2,2,2],[-2,1,4]]);
V:=Vector([s,s^2,s^3]);#V:=Vector([cos(s),sin(s),cos(s)]);
X0:=Vector([1,2,3]);
S1:=MatrixVectorMultiply(MatrixExponential(ScalarMultiply(A,t)),X0);
B:=MatrixVectorMultiply(MatrixExponential(ScalarMultiply(A,t-s)),V):
S2:=Vector([int(B[1],s=0..t),int(B[2],s=0..t),int(B[3],s=0..t)]);
S:=VectorAdd(S1,S2);
A:=Matrix([[0,1,0],[0,0,1],[1,1,-1]]);
V:=Vector([0,0,cos(t)]);
X0:=Vector([1,0,0]);
S1:=MatrixVectorMultiply(MatrixExponential(ScalarMultiply(A,t)),X0);
B:=MatrixVectorMultiply(MatrixExponential(ScalarMultiply(A,t-s)),V):
S2:=Vector([int(B[1],s=0..t),int(B[2],s=0..t),int(B[3],s=0..t)]);
S:=VectorAdd(S1,S2);
diff(S[2],t);
systemeDiff:=proc(A,X)
local i,n,L,D;
n:=ColumnDimension(A);
L:=Eigenvectors(A);
D:=DiagonalMatrix(L[1]);
for i to n do D[i,i]:=exp(D[i,i]*t) od;
D,MatrixVectorMultiply(D,X);
end:
A:=Matrix([[-5,2,4,-4],[10,-3,-6,8],[11,-4,-6,8],[22,-8,-14,17]]);
X:=Vector(<x,y,z,t>);
systemeDiff(A,X);