# Writings

### Integration Theories

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 …

### Moore-Osgood Theorem

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

### Jacobi Iteration Method

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

### Volume of Simplices

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

### Logical Formulae

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

### Colloquium Notes: Craig Evans

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

### Lengths of Parallel Curves

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

### A Criterion for Real Roots

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

### You are 23 times more likely to crash

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

### A Tangent Identity

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