In
[1, p. 34 exercise 2.9] we are asked to prove that the rank of the complex

matrix
where the

are linearly independent complex

vectors and the

‘s are real and positive, is equal to

if

. Furthermore we are asked what the rank equals to if

>

.
read the conclusion >
Author: Panagiotis
22
Dez
In exercise
[1, p. 34 exercise 2.8] we are asked to find the inverse of the

hermitian matrix

given by
[1, (2.27)] by recursively applying Woodbury’s identity. This should be done by considering the cases where

are arbitrary and where

,

for

beeing distinct integers in the range
![\left[ -n/2,n/2-1 \right]](https://lysario.de/wp-content/cache/tex_349760367e158b72823c089231e45245.png)
for

even and
![\left[ -(n-1)/2,(n-1)/2 \right]](https://lysario.de/wp-content/cache/tex_bbbbf77ffaa65be463cde297b83e452b.png)
for

odd.
read the conclusion >
Author: Panagiotis
20
Nov
In exercise
[1, p. 34 exercise 2.7] it is requested to find the inverse of the real symmetric Toeplitz matrix
and show that it is symmetric and persymmetric.
read the conclusion >
Author: Panagiotis
16
Nov
In problem
[1, p. 34 exercise 2.6] we are asked to prove that if

and

are complex

Hermitian matrices and

is positive semidefinite, then
![\left[\mathbf{A}\right]_{ii} \geq \left[\mathbf{B}\right]_{ii}](https://lysario.de/wp-content/cache/tex_3652289cddad029917d54c1a0ed7c8cd.png)
.
read the conclusion >
Author: Panagiotis
27
Sep
In exercise
[1, p. 34 exercise 2.3] we are asked to prove that the normalized DFT matrix given in
[1, p. 21, (2.22)] is unitary.
read the conclusion >