Linear Algebra Homework 1
Problem 1 - 1ex
Let
Solve for X the matrix equation
A + 2X = B
Do it first by adding matrices on the left hand side and
then comparing the entries of the
resulting matrix and matrix B. Then solve it again using matrix algebra.
Problem 2 - 2ex
(a) Let
Compute
(b) Show that for any square matrix is a symmetric matrix.
Problem 3 - 2ex
Let A be a square matrix. For which combinations of
scalars α and β the matrix
is a symmetric matrix.
Problem 4 - 1ex
Let A and B are two symmetric matrices. Show that A + B is symmetric.
Problem 5 - 1ex
Let A and B are two symmetric matrices. For which combinations of scalars α and β the matrix is a symmetric matrix.
Problem 6 - 1ex
Let A be a symmetric matrix. Show the matrix αI + A is a symmetric matrix.
Problem 7 - 2ex
Let A and B are two square matrices. Let C = A − B is a
symmetric matrix. What does
that tell you about matrices A and B?
Problem 8 - 1ex
A matrix is an upper triangular matrix if all its entries
under the diagonal are 0.
Let A and B are two upper triangular matrices. For which combinations of scalars
α and β
the matrix is an upper triangular matrix.