Paper 1 · Functions and Graphs
⏱ Tested in 4 exam questions since 2016
Lesson 5 of 10
Functions and Graphs 5: Injective Functions
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- Define injective (one-to-one): every output has a unique input
- Test injectivity with a broken horizontal line — at most one intersection
- Explain why x² fails the test but 1/x (with x ≠ 0 excluded) passes
Most recent exam questions
- 2025 P1 Q4(b) — deferred
- 2023 P1 Q5(c)(ii)
- 2022 P1 Q6(b)(ii) — deferred
- 2016 P1 Q5(b)(i)
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