Fingerprint GUI not installing in Ubuntu 20.04
I'm trying to install fingerprint-gui on my Lenovo Ideapad 520 having Ubuntu 20.04 on which fingerprint isn't working for now. I tried going dir...
04 Apr 2026 1 READS
USB camera is not detected anymore
I have a USB camera which used to work just fine, as plug-and-play, on my Ubuntu (current version 18.04.4 LTS, Linux E480 4.15.0-88-generic #88-Ubuntu SMP...
04 Apr 2026 0 READS
How to compare two lines in a txt file with bash?
I would like to compare the two last lines from the txt file. While it looks like comparing line by line is out there - found few examples - I cant seem t...
04 Apr 2026 1 READS
Finding the associated unit eigenvector
Background Find the eigenvalues $λ_1<λ_2$ and two associated unit eigenvectors of the symmetric matrix $$A = \begin{bmatrix}-7&12\\12&11\end{bm...
04 Apr 2026 0 READS
Extended Euclidean Algorithm for Modular Inverse
I'm currently learning how to find the inverse of a modulo with the Extended Euclid Algorithm and I stumbled upon a problem when finding an inverse w...
04 Apr 2026 1 READS
A detail in the proof of Auslander-Buchsbaum Theorem
I'm trying to understand the proof of a theorem (Auslander-Buchsbaum) which says that given a local ring $(R,m)$, where $m$ is the maximal ideal, and...
04 Apr 2026 0 READS
No “Performance” option in “Power Mode” in Ubuntu 21.04
I have Ubuntu 21.04 installed on my laptop. There is supposed to be a “Performance” option in Settings > Power Mode, but I am only given the options fo...
04 Apr 2026 0 READS
Set up sudo so that a particular common user can edit /etc/fstab
How can I set up sudo so that a particular common user can edit /etc/fstab? I've thought to edit /etc/sudoers.d file to do this, but how do we edit /...
04 Apr 2026 0 READS
Why (Zn,*), integers modulo n under multiplication, is a group if and only if n is prime?
Is it true that $(\Bbb Z_n,\cdot)$, integers modulo $n$ under multiplication, is a group if and only if $n$ is prime? If it's true, why? How can I pr...
04 Apr 2026 0 READS
Are all polynomial expressions an algebraic expression.
I mean to ask that, real numbers can be written in the form of constant polynomials like, 4x^0, 2x^0 etc. If all polynomial expressions are algebraic expr...
04 Apr 2026 0 READS
