Different use of approximate equality symbols
I have been wondering for a long time whether there is a unequivocal way to define and use the symbols commonly adopted for an approximate equality betwee...
19 Apr 2026 1 READS
Archive: News
Identity tensor as a tensor product of two vectors
Any second order tensor in a given basis can be expressed as a matrix. Also, as any second order tensor can be expressed a tensor product of two first ord...
19 Apr 2026 1 READS
Showing $a^2 + b^2 > 2ab$ without using the fact that $(a-b)^2 = a^2 + b^2 -2ab$?
I am wondering if we can Show that $a^2 + b^2 > 2ab$ without using the fact that $(a-b)^2 = a^2 + b^2 -2ab$? (I'm particularly interested in $0<...
19 Apr 2026 1 READS
Implication and equivalence arrows, when to use them?
In my course book we have something called implication arrows $\Rightarrow$ and equivalence arrows $\Leftrightarrow$ and I have never managed to understan...
19 Apr 2026 1 READS
![How do you find the area of a parallelogram with the vertices? [closed]](https://edu.smbbmcl.edu.pk/uploads/how-do-you-find-the-area-of-a-parallelogram-with-the-vertices-closed_720.jpg)
How do you find the area of a parallelogram with the vertices? [closed]
How do you find the area of a parallelogram with the following vertices; $A(4,2)$, $B(8,4)$, $C(9,6)$ and $D(13,8)$.
19 Apr 2026 1 READS
Why is a double exponential function faster than $x!$?
Reading this wikipedia article I found an interesting sentence: Factorials grow faster than exponential functions, but much slower than double-exponential...
19 Apr 2026 1 READS
Are there skew lines in more than 3 dimensions?
In our environment, two straight lines are, in general, skew lines. The term skew means that the straight lines are not parallel, do not cross, and most i...
19 Apr 2026 1 READS
Matrices which are both unitary and Hermitian
Matrices such as $$ \begin{bmatrix} \cos\theta & \sin\theta \\ \sin\theta & -\cos\theta \end{bmatrix} \text{ or } \begin{bmatrix} \cos\theta &...
19 Apr 2026 1 READS
What is the idea behind a projection operator? What does it do?
I know what a projection operator is, but I am unable to explain it in words without using mathematical symbols. Can anyone help me? I don't need exa...
19 Apr 2026 1 READS
rearranging matrix equation and solving/isolating for X matrix
For whatever reason the only part of my linear algebra class I am struggling with is manipulating matrices equations to solve and isolate for a certain ma...
19 Apr 2026 1 READS
