email

Unregistered less info
68 reputation
17
bio website
location
age
visits member for 1 year, 6 months
seen Dec 13 '12 at 14:13

Dec
7
awarded  Popular Question
Nov
7
awarded  Notable Question
Aug
24
awarded  Popular Question
Dec
10
accepted Determinant of anti-diagonal permutation matrix
Dec
10
asked Determinant of anti-diagonal permutation matrix
Dec
7
comment Polar decomposition
OMG! That's my huge mistake! I corrected the number in the first matrix!
Dec
7
revised Polar decomposition
deleted 1 characters in body
Dec
7
comment Polar decomposition
That example is from the textbook. Is that wrong?
Dec
7
asked Polar decomposition
Dec
3
accepted Does zero vector have zero dimension?
Dec
3
comment Does zero vector have zero dimension?
Yes, but the problem is that I have no idea how to apply the rank-nullity theorem in here. Please state details then I can follow it.
Dec
3
asked Does zero vector have zero dimension?
Dec
2
awarded  Commentator
Dec
2
comment Linearly independent and orthogonality
I found counter example $x_1=(1, 0), x_2=(2, 1)$, they are linearly independent but not orthogonal. So the inverse is not true, right?
Dec
2
asked Linearly independent and orthogonality
Nov
27
comment The existence of second derivative
Thanks! I'd like to check to accept your answer but don't know why it doesn't work.
Nov
27
awarded  Custodian
Nov
27
reviewed Approve suggested edit on The existence of second derivative
Nov
27
asked The existence of second derivative
Nov
25
comment If $N$ is normal, show that $\begin{Vmatrix} Nx \end{Vmatrix}$=$\begin{Vmatrix} N^{H}x \end{Vmatrix}$ for every vector $x$
And from the second to third, it is because the length is the same even though it is transposed? I mean, $\|A^H\|$=$\|A\|$?