Another Angle

Another Angle

Animated explanations of the math behind economics and business — built so the idea arrives first and the formula second.

Series

Intuitive math for economics

Four chapters so far, walking from ratios up toward multivariable calculus. One chapter, one way of seeing.

Essays

The same ideas, written down

A video is a bad place to answer a specific question. These pages answer one each, with the answer up front.

Game

Walk inside a function

Type z = f(x, y) and a 3D island becomes that graph. Runs in the browser, no install.

Newest chapter

Linear Algebra Explained in 6 Minutes

A vector is a building block for movement, and its coordinates are just how many times you use each block. Know where the basis vectors land, and you know where everything lands.

About this chapter →


The series

Intuitive Math for Economics and Business

The minimum math you need, explained intuitively. Each chapter installs a schema — a way of seeing — rather than a procedure to memorise. They build on each other, but each one stands on its own.

Chapter 1

A Ratio Is Simply a Tool for Comparison

A ratio is the size B would have if you called A's size 1. A percentage is the same idea with 100 instead — and crucially, it needn't be a slice of a whole.

Chapter 2

The Derivative Is a Nudge Ratio

Set the input nudge to 1 and the output nudge is the derivative. That's all df/dx means — and it's exactly what "marginal" means in economics.

Chapter 3

Trigonometry, Direction and the Unit Circle

An angle is the length of the arc it cuts from a circle of radius 1. Sine and cosine are the two heights you climb walking a distance of 1 from the origin.

Chapter 4

Linear Algebra Explained in 6 Minutes

Vectors as building blocks for movement, and transformations that move the whole space at once.

All chapters and what's next

Open World Discover

Some things you have to stand on

A 3D open world that runs in your browser, where the island is a function. Type z = f(x, y) and the terrain becomes that graph — then drive, fly, or walk across it.

Read instead of watch

Some answers are better written down

You can't skim a video, and you can't quote one. So the ideas also live here as writing — one concept per page, with the answer in the first paragraph.

Ratio

A ratio isn't a slice of a whole

Why a percentage is allowed to pass 100%, and what separates a ratio from a proportion.

Derivative

"Marginal" is just the economist's word for a derivative

Marginal cost is dTC/dQ — and MR = MC is the first-derivative test in a business suit.

Trigonometry

Slope and angle aren't the same number

Why a 15% treadmill incline is about 8.5°, not 15° — and why grade and degrees drift apart as the hill steepens.

Linear algebra

Coordinates are counts of building blocks

What a basis vector is, and why the columns of a matrix are simply where the basis vectors landed.

All essays