Series

Intuitive Math for Economics and Business

The minimum math you need, explained intuitively.

This series rebuilds calculus and its neighbours not as a set of procedures but as a handful of schemas — ways of seeing that you can carry into any problem. One chapter, one schema. They build on each other, so the order matters more than usual, but each one is self-contained enough to watch alone.

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. Crucially, it needn't be a slice of a whole.

Chapter 2

The Derivative Is a Nudge Ratio

The ratio of the output nudge to the input nudge. Set dx to 1 and the output nudge is the derivative — which is also 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 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. If you know where the basis vectors land, you know where every point lands.

What's next

The series keeps going up the same staircase: from one variable to several, and from derivatives to integrals.

• Two-variable functions and the directional derivative — the nudge-ratio schema, one dimension up. In production.
• Integrals — in early notes.
• A chapter zero on schemas themselves — what this whole series means by "a way of seeing". Drafted.

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