updates
Is the $L$ in $LU$ factorization unique?
I was doing an $LU$ factorization problem \begin{bmatrix} 2 & 3 & 2 \\ 4 & 13 & 9 \\ -6 & 5 &4 \end{bmatrix} and I was going to mu...
Apr 15, 2026
Archive: Updates
updates
How to intuitively understand parallel transport
In the article I've referenced below, and many other articles for that matter, the notion of parallel transport along a line of latitude $\theta=\the...
Apr 15, 2026
updates
How to solve limit of this function?
$\lim_{x\to 1} \frac{x^2 -3x+2}{(x^3-2x^2+x)^2} $ I have tried: 1) substitution of $x$ by $1+\epsilon$(this gets long) 2) factorizing and simplifying I ha...
Apr 15, 2026
updates
Can someone explain Cayley's Theorem step by step?
This is from Fraleigh's First Course in Abstract Algebra (page 82, Theorem 8.16) and I keep having hard time understanding its proof. I understand on...
Apr 15, 2026
updates
Proving $\cos 36° > \tan 36° $
How do we prove that $\cos 36° > \tan 36° $ ? Please help . Thank you.
Apr 15, 2026
updates
My teacher describes absolute value confusingly: $|x|=\pm x,\quad \text{if}\enspace x>0 $.
He says (direct quote): "In higher mathematics the absolute value of a number, $|x|$, is equal to positive and negative $x$, if $x$ is a positive number."...
Apr 15, 2026
updates
$A = Pe^{rt}$? How do I properly calculate this?
So, I have a word problem that I need to use the formula $A = Pe^{rt}$ to solve... Suppose $2000 is invested at an interest rate 2.75% compounded continuo...
Apr 15, 2026
updates
Type of set theory in Halmos' naive set theory.
The title of Paul Halmos' book Naive Set Theory suggests that it treats set theory naively rather than axiomatically. However, the book constructs se...
Apr 15, 2026
updates
User Subramanyam Durbha - Mathematics Stack Exchange
Q&A for people studying math at any level and professionals in related fields
Apr 15, 2026
updates
An aclaration on the collection of cosets of some group $G$
Suppose $G$ is a finite group and $H$ a subgroup of $G$. Put $G = \{ g_1,...,g_n \}$ and let $\mathcal{L} = \{ g_1H,...,g_nH \}$ be the set of left of cos...
Apr 15, 2026
