# Archive

Sorted by tags. Here’s the archive page sorted by categories or by date.

**Maths tags:**[Alg top] [Calculus] [Complex analysis] [Diff eqs] [Diff geom] [Dynamical systems] [Group theory] [Lie groups] [Linear algebra] [Number theory] [Physics] [Proj geom] [Real analysis] [Topology]

**Other tags:**[Book reviews] [Life@Oxford] [Movie reviews] [Oxford admissions] [Secondary maths]

### Alg top

### Calculus

### Complex analysis

### Diff eqs

### Diff geom

- Understanding the hyperbolic plane with refraction
- Geometry of curves and projectile motion
- Applications of Lie Groups to Differential Equations
- Levi-Civita Symbol (Part II)
- Levi-Civita Symbol (Part I)

### Dynamical systems

- A circle and a hyperbola living in one plot
- Visualising bifurications
- Visualising linear dynamical systems directly

### Group theory

- Visualising composition series
- Visualising the group isomorphism theorems
- Structures closed under intersections

### Lie groups

### Linear algebra

- A circle and a hyperbola living in one plot
- Using matrices to understand polynomials
- Visualising linear dynamical systems directly
- Visualising invertibility and diagonalisability of matrices
- Euclidean algorithm and GL(2, Z)
- Understanding the dual space
- Understanding the Jordan Normal Form
- Three ways of thinking about matrix multiplication
- Showing preservation of properties under multiplication via difference of squares

### Number theory

### Physics

- A physical interepertation of trigonometric substitution
- Partial derivatives of the radius
- Understanding the hyperbolic plane with refraction
- Understanding potential wells
- Calculus of inverse functions: Inverse function theorem and the Legendre transformation (Part I)
- Constructing homotopies using gravity
- Geometry of curves and projectile motion
- Applications of Lie Groups to Differential Equations
- Levi-Civita Symbol (Part II)
- Levi-Civita Symbol (Part I)

### Proj geom

- The Gudermannian
- A physical interepertation of trigonometric substitution
- Visualising invertibility and diagonalisability of matrices
- Understanding linear fractional transformations
- Playing with the real projective plane

### Real analysis

- Understanding Green's theorem
- Another visualization of the second fundamental theorem of calculus
- Calculus of inverse functions: Inverse function theorem and the Legendre transformation (Part I)
- Complex function plotter
- Pedagogically weaker notions of continuity
- Structures closed under intersections
- Extending sequences into smooth functions using trignometric functions
- Showing preservation of properties under multiplication via difference of squares
- Another example of pointwise but not uniform convergence

### Topology

- Alternate notation for topology
- Generalising function plots to topological spaces
- Structures closed under unions
- Structures closed under intersections
- Interiors, closures and boundaries of topological spaces

## Other tags

### Book reviews

- From Immigrant to Inventor - Mihajlo Pupin
- The Creative Act - Rick Rubin
- I Want to be a Mathematician - Paul Halmos
- The Art of Doing Science and Engineering - Richard Hamming

### Life@Oxford

- Third Easter in Oxford
- Eighth Term at Oxford
- Third Christmas in Oxford
- Seventh Term at Oxford
- Second Summer in Oxford
- Second Year at Oxford
- Second Easter in Oxford
- Fifth Term at Oxford
- Second Christmas in Oxford
- Fourth Term at Oxford
- First Summer in Oxford
- First Year at Oxford
- Second Term at Oxford
- First Term at Oxford

### Movie reviews

### Oxford admissions

- Graph sketching techniques
- Tackling Oxford Mathematics Interviews (Undergraduate)
- Making a mathematics personal statement personal
- Tackling the Oxford MAT
- Choosing a college at Oxford (Undergraduate)
- Applying to Oxford Mathematics (Undergraduate)

### Secondary maths

- Graph sketching techniques
- Understanding linear fractional transformations
- Calculator Programming
- Introduction to symmetries and its applications
- Opportunities learning maths beyond the syllabus in HK
- Three ways of thinking about matrix multiplication
- HKDSE Physics and M2 (Part III)
- HKDSE Physics and M2 (Part II)
- HKDSE Physics and M2 (Part I)
- Euler's formula and compound angle formulae