Math 1554 - Study guides, Class notes & Summaries

If x1 maximizes a quadratic form, subject to the constraint ||x1||=1, then - so does -x1 If A= A^T x != y, Ax = 3x, and Ay = -y, then - x^Ty = 0 S = {x exists in R^3 | x1 + x2 + x3 = 1}, then - is not a subspace of R^3 If U is an echelon form of matrix A, then - Col(U) != Col(A) Row operations on a nxn matrix do change - its eigenvalues. IF A exists in R^nxn and x and y are vectors in R^n, then Ax * Ay = - x^T(A^T)Ay If the eigenvalues of a 3x3 matrix A are 1,2,4 and A = PBP^-1 for 3x3 mat...

If A and B are invertible nxn matrices, then the product AB is also invertible. - True If Ax = 0 for some x =/= 0, then the matrix A is not invertible. - True If matrix A is row reduced to echelon form to produce matrix E, then the column spaces of A and E have the same dimension. - True Any set of vectors which span all of R3 is automatically a basis for R3. - False If λ=0 is an eigenvalue of A, then the matrix A is non-singular. - False If A and B are nxn matrices and det(AB) =/= 0, th...