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Understanding Functions Worksheet

Grade 8 Math · printable worksheet (PDF) with answer key · 14 problems · CCSS 8.F.A.1, 8.F.A.2

A printable grade 8 understanding functions practice worksheet with 14 problems and a complete, step-by-step answer key — formatted to print cleanly on standard paper. Download the problem set and answer key below for free.

Sample problems

A function assigns exactly one output to each input. Decide whether each relation is a function, evaluate functions at given inputs, and read input/output tables.

1. Does the set of ordered pairs ${(1, 3), (2, 5), (3, 7), (4, 9)}$ represent a function? Explain.
2. Does the set ${(2, 4), (3, 6), (2, 8), (5, 10)}$ represent a function? Explain.
3. Which mapping represents a function?
- $1 \to a, 1 \to b, 2 \to c$
- $1 \to a, 2 \to a, 3 \to b$
- $2 \to a, 2 \to b, 3 \to c$
- $4 \to a, 4 \to b$
4. The function is given by $f (x) = 3 x + 2$ . Find $f (4)$ .

Plus 10 more problems and a full answer key in the PDF.

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Problem set (PDF)Answer key (PDF)

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