What is FUNCTION?: Beyond the Formula

Описание: What is a function, really?

Most people think a function is just a formula like
f(x) = x/2

But that’s only part of the story.

In this visual lesson, we rebuild the concept of relations and functions from first principles: not memorized rules, not tricks, but structure.

We start with sets.
→ We define domain, codomain, and range properly.
→ We clarify why f is the function, not f(x).
→ We see why the rule alone does NOT define a function.
→ We connect formulas to graphs through ordered pairs.
→ And finally, we understand the Vertical Line Test from the definition (not as a trick, but as a logical consequence.)

By the end, the famous Vertical Line Test won’t feel like a trick, it will feel inevitable.

🔹 Understand why a function is more than just a rule
🔹 See why domain and codomain are part of the definition
🔹 Discover how ordered pairs become graphs
🔹 Learn why one input must connect to exactly one output
🔹 Finally understand the Vertical Line Test

This isn’t about memorizing procedures.
It’s about seeing structure.

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📚 Continue Learning (Completely FREE)
Practice visualizing graphs and domains interactively:
👉 Explore functions on GeoGebra & Desmos
GeoGebra: https://www.geogebra.org/geometry/zrz...
Desmos: https://classroom.amplify.com/activit...
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📚 Part of the C-Infinity Series
Exploring structure, geometry, and the hidden architecture behind mathematics.

✨ Subscribe for more math visualizations that make abstract ideas feel real:
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🎥 Chapters
0:00 Relation and Function
2:14 Domain, codomain, and rule
3:20 What makes a function a function?
4:07 Applying the definition on numbers
6:54 Graph of the Function
8:21 The Vertical Line Test
9:35 Today's Summary

#maths #function #education #relation #algebra #precalculus #ibmath