# Xah Math

Math related things i've written.

Subscribe: Xah Math Blog.

### A Visual Dictionary of Special Plane Curves

### Geometry: Gallery of Surfaces

### Discontinuous Groups of Rotation and Translation in the Plane

### Math Graphics Gallery

### Intro to POV-Ray and 3D Geometry Programing

### Great Math Software

### Geometric Transformation on the Plane

### Intro to Real Projective Plane

### Notes on A New Kind of Science

### Crop Circle Gallery

- What is Technical Drawing, Descriptive Geometry, Projective Geometry, Linear Algebra
- Intro to POV-Ray and 3D Geometry Programing
- The Codification of Mathematics

## Math Notation, Syntax, Formal Language

See: Math Notations, Computer Language Notations, and the “Form” in Formalism (~45 articles)

## Misc Random Notes

- The Geometric Significance of Complex Conjugate
- Multiplication and Multiplicative Identity
- Understanding Complex Numbers
- John Baez on Octonion 📺
- The Significance of Complex Numbers: Frobenius Theorem
- 1+2+3+4+… = -1/12, Ramanujan's Sum 📺
- Adaptive Sampling, Plotting Math Curve

- the Nature of Associative Property of Algebra
- Euler Angles Can Cause Gimbal Lock, But Not Quaternions
- Bird Flight V Formation as Geometry Problem of Max Visual Contact
- the Nature of Linear Transformation
- What's the Nature of Eigenvector?
- On the Nomenclature of Eigenvector and the Igon Value Problem
- What's Difference Set of a Group

- What is Riemann Surface? Understanding the Concept Without Math
- Klein Bottle Checker Board Paradox
- Learning Notes Of Symmetric Space and Differential Geometry Topics
- Reading Notes on Nicolas Bourbaki
- What is Quadratic Form in Math?
- Space-Filling Curve
- Reading Notes on Tilings and Patterns

### Misc Fun Visual Geometry

## Math Eye Candy

### polyhedron

### tiling and patterns

### recursion

### illusion

## Random Social Commentary

- Grigori Perelman and Money
- Math Prizes and Nobel Ignobility
- Alexander Grothendieck = Obi-Wan
- Math Politics: Simon Plouffe and nth Digit Formula of π
- Twin Prime Conjecture Breakthru: Yitang Zhang
- Martin Gardner (1914 to 2010)
- Mathematician Marijke Van Gans Died (1955 to 2009)
- Russell Towle Died (1949 to 2008)
- Robby Villegas Died (1968 to 2010)
- What and Why Mathematics?

## Math Books

- Free Math Textbooks
- Math and Geometry Books
- Top Ten Math Books for Math Haters
- A Survey of Mathematica Books 1997
- Math Books Keeping and Reading

#### misc

- Xah's Top 10 Math Wonders
- Math Mysticism: is Hurricane Shape a Fibonaci Spiral?
- Math: Fibonaci Sequence Video Fallacy 📺

#### misc, unsorted

- English/Chinese Math Terminology 中/英 数学术语
- Stereographic Projection 3D-Printed Physical Model
- Orbits in Juggling's Siteswap Notation
- Tron Light Cycle Optimal Strategy
- Ladybug Video Game, Optimal Strategy
- Maze and Math in Video Games
- Bejeweled Blitz Strategy as Math
- Geometry: Ellipses, Linkages, Solids of Constant Width 📺
- Plants vs Zombie; Thoughts on Strategy and Game Formulation
- Why Are Scores in Video Games Mega Huge?

- What's a Year? Why Not Just 100 Days?
- What Voting Systems are There?
- Modeling Math Problem Into a Question in Formal Language

- HP-28S Advanced Scientific Calculator
- What's the Latest and Greatest in Calculators?
- 3D Visualization Design

- Math: ID System, Number Base vs Number of Digits
- math simulation ideas
- ants, insects, decentralized systems
- Notes On Plane Curves and Proofs
- Principia Mathematica

- Theory Of Equations
- Review of Khan Academy by Xah Lee
- The Logical Levels of Interpretation
- Math Formula For Beauty
- Dead Reckoning in a Non-Orientable 3D Space
- Math, Algebra: On the Phraseology of X Over K
- Schmidt Arrangement, Algebra Integer, Gaussian Integer, Eisenstein Integer, Modular Group
- Extending the Euclidean Plane: Riemann Sphere and Real Projective Plane
- Combinatorics, Algorithm, and Humanity
- Go Game: Google AlphaGo vs Lee Sedol
- Why Are Text Book So Expensive?
- Geometer's Sketchpad Closed Shop?

If you have a question, put $5 at patreon and message me.