Since I am preparing to teach intro real analysis this fall, it is a good time for me to get reacquainted with Riemann integration and …

This short post aims at proving a general version of the Moore-Osgood Theorem on interchanging of limits.
Theorem …

Summary of the Jacobi iteration method in numerical linear algebra, and some caveats.

How to compute the volume of a simplex using the Cayley-Menger determinant, and a higher dimensional Pythagorean theorem

Since the COVID-19 crisis and the university moving to online instruction, I've spent too much time programming WeBWorK assignments. …

L. Craig Evans is a professor at UC Berkeley. For many students he is best known for his textbook on partial differential equations. I …

Let's start with something simple: Given a circle with radius $R$, draw a concentric circle with radius 1 larger. How much longer is …

When does a polynomial with real coefficients have only real roots? Here's one way to determine it.

Driving down the highway in upstate Michigan yesterday, I saw a State Police billboard that states (I paraphrase)
Drivers who text are …

Here's a slightly non-obvious relation between some angles, that I ran into accidentally.
Claim: (angles below given in degrees)
\[ …