Two Layers, Read Separately

You’ll learnto describe how a curve changes with two separate reads: which way the output goes, and what its rate of change is doing.

A curve records two quantities moving together, and describing it takes two questions asked in order. Which way does the output go? And are its changes growing or shrinking? Those are separate layers, and answering the second from the first is the most expensive habit in Unit 1. Twelve short steps; press Next for each one.

12 STEPS · 6 QUICK CHECKS · DIRECTION · CONCAVITY · Δ TABLES · v3

direction is the output; concavity is the rate

Before you start

What you're looking at

A single curve linking an input to an output. As the input slides to the right, the output responds and the marked point traces the curve.

The question

Which way does the output move — and are its changes growing or shrinking as it goes?

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