Tiny example
Input and output
For the rule y = 2x + 1, try x = 0, 1, 2.
The outputs are 1, 3, 5. Plotting them begins to reveal a line.
Functions and graphs
Rules and pictures for relationships between quantities.
A function takes an input and produces an output. A graph lets you see the relationship across many inputs at once.
Why it matters
Functions and graphs connect algebra, change, modelling, transformations and data.
Things to watch for
- Thinking a graph is just a picture rather than a set of relationships.
- Mixing up input and output.
- Forgetting that changing the equation changes the graph.
Where it connects
functionsgraphsalgebra
Try it in a tool
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