Matrices - Conditions for $AB+BA=0$ - Mathematics Stack Exchange
As long as a, b, c a, b, c are not all 0 0, this has rank 2 2, so there is a 2 2 -dimensional linear space of B B for which AB + BA = 0 A B + B A = 0 in this case. On ...
How many ways can we get 2 a's and 2 b's from aabb?
Because abab is the same as aabb. I was how to solve these problems with the blank slot method, i.e. _ _ _ _. If I do this manually, it's clear to me the answer is 6, aabb abab abba baba bbaa baab Which is …
11 | abba, where a and b are the digits in a 4 digit number.
Nov 21, 2013 · Truly lost here, I know abba could look anything like 1221 or even 9999. However how do I prove 11 divides all of the possiblities?
How to calculate total combinations for AABB and ABBB sets?
Apr 19, 2022 · Although both belong to a much broad combination of N=2 and n=4 (AAAA, ABBA, BBBB...), where order matters and repetition is allowed, both can be rearranged in different ways: …
sequences and series - The Perfect Sharing Algorithm (ABBABAAB ...
Oct 4, 2016 · The algorithm is normally created by taking AB, then inverting each 2-state 'digit' and sticking it on the end (ABBA). You then take this entire sequence and repeat the process (ABBABAAB).
How many $4$-digit palindromes are divisible by $3$?
Feb 28, 2018 · 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 …
elementary number theory - Divisibility Tests for Palindromes ...
I've found and proven the following extensions to palindromes of the usual divisibility rules for 3 and 9: A palindrome is divisible by 27 if and only if its digit sum is. A palindrome is divisible by 81 if and only if …
CW complex for Möbius strip and its homeomorfisams
Jan 14, 2023 · According to this question, there is CW complex with one 0-cell,one 1-cell and one 2-cell. No such CW structure exists on the the Möbius strip. Moreover the linked question doesn't claim that, …
Prove - Mathematics Stack Exchange
Aug 31, 2019 · A A and B B are hermitian, so I know they must commute. So AB − BA = 0 A B B A = 0. But I don't think I can get very far with that. I just totally don't know how to start. Some help would be …
How to show that $A^2=AB+BA$ implies $\det (AB-BA)=0$ for …
Jan 26, 2015 · Let $A$ and $B$ be two $3\times 3$ matrices with complex entries such that $A^2=AB+BA$. Prove that $\det (AB-BA)=0$. (Is the above result true for matrices with real ...