📈ap pre-calculus review

Horizontal line test

Written by the Fiveable Content Team • Last updated August 2025
Verified for the 2027 exam
Verified for the 2027 examWritten by the Fiveable Content Team • Last updated August 2025

Definition

A graphical method to determine if a function is one-to-one: if any horizontal line intersects the graph more than once, the function is not one-to-one and does not have an inverse.

AP course connection

Topic 2.8: 2.8 Inverse Functions

Unit 2

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