- Feb 6, 2023
Both the Gini coefficient and the variance are measures of statistical dispersion. We are then motivated to find the relationship between them. It turns out that there is a neat mathematical relationship between them.
- Feb 4, 2023
Personally, I have the demand of handwriting math/physics notes, but an annoying fact about this is that I usually cannot distinguish every letter that may be possibly used well enough. In this article, I will try to settle this problem.
- Feb 3, 2023
何为手纸本?
- Feb 3, 2023
Bra–ket notation is a good-looking notation! I am sad that it is not generally taught in math courses. Let me introduce it to you.
- Feb 2, 2023
We try solving the even function solutions to the time-independent Schrödinger equation for the potential V=−α∑j=−nnδ(x−ja) such that E<0 (bound states).
- Feb 1, 2023
The aliens intiated their attack to the earth! They shoot bullets with mass m and speed v from a far-awar planet. To defend, humans built a field U=α/r that can repel the bullets. What regions are safe? The answer turns out to be the interior of a circular paraboloid.