copy and paste this google map to your website or blog!
Press copy button and paste into your blog or website.
(Please switch to 'HTML' mode when posting into your blog. Examples: WordPress Example, Blogger Example)
Input Form:Deal with this potential dealer,buyer,seller,supplier,manufacturer,exporter,importer
(Any information to deal,buy, sell, quote for products or service)
How many $4$-digit palindromes are divisible by $3$? How many 4 4 -digit palindromes are divisible by 3 3? I'm trying to figure this one out I know that if a number is divisible by 3 3, then the sum of its digits is divisible by 3 3 All I have done is listed out lots of numbers that work I haven't developed a nice technique for this yet
matrices - When will $AB=BA$? - Mathematics Stack Exchange Given two square matrices A, B A, B with same dimension, what conditions will lead to this result? Or what result will this condition lead to? I thought this is a quite simple question, but I can find little information about it Thanks
linear algebra - Does $\det (A + B) = \det (A) + \det (B)$ hold . . . But you are expected to think a bit about things before asking questions Sure, part of the question would still make sense to ask, but you would probably have known that the equality does not hold in general, and people might be focusing more on the more tricky part of the question
Proofs of determinants of block matrices [duplicate] I know that there are three important results when taking the Determinants of Block matrices $$\\begin{align}\\det \\begin{bmatrix} A amp; B \\\\ 0 amp; D \\end
The commutator of two matrices - Mathematics Stack Exchange The commutator [X, Y] of two matrices is defined by the equation $$\begin {align} [X, Y] = XY − YX \end {align}$$ Two anti-commuting matrices A and B satisfy $$\begin {align} A^2=I \qu
Show that $ e^{A+B}=e^A e^B$ - e^ {A+B}=e^A e^B$ - Mathematics Stack . . . As a remark, it is actually legitimate to assume that A A and B B are simultaneously diagonalisable (surprise, surprise!), so the proposition is trivial But obviously, the reason why we can make such an assumption is way beyond the scope of undergraduate (or even graduate) linear algebra courses
If eigenvalues are positive, is the matrix positive definite? This question does a great job of illustrating the problem with thinking about these things in terms of coordinates The thing that is positive-definite is not a matrix M M but the quadratic form x ↦ xTMx x ↦ x T M x, which is a very different beast from the linear transformation x ↦ Mx x ↦ M x For one thing, the quadratic form does not depend on the antisymmetric part of M M, so
Trace of AB = Trace of BA - Mathematics Stack Exchange We can define trace if A =∑i ei, Aei A = ∑ i e i, A e i where ei e i 's are standard column vectors, and x, y =xty x, y = x t y for suitable column vectors x, y x, y With this set up, I want to prove trace of AB and BA are same, so it's enough to prove that