Florida B.E.S.T. MA.912.F.3.6

MathGrades 9–12Create new functions from existing functions.

The Standard

Determine whether an inverse function exists by analyzing tables, graphs and equations.

Florida B.E.S.T. Standards for Mathematics

Teacher's field guide

What This Standard Means

What Students Need to Do

Students decide whether reversing input and output values still produces a function. They use repeated outputs, the horizontal line test, or algebraic reasoning to support the decision.

What Mastery Looks Like

Students correctly identify repeated outputs in a table, multiple intersections on a graph, or equal outputs from different inputs in an equation. They justify each decision and can suggest a domain restriction when needed.

Common Misconceptions

Students often confuse an inverse function with a reciprocal, writing 1/f(x). They may use the vertical line test instead of the horizontal line test. They may also ignore the stated domain when deciding whether outputs repeat.

How to Assess It

Exit ticket: For f(x) = x² - 4 on all real numbers, decide whether its inverse is a function. Justify your answer and give a domain restriction that would change the result.

Lesson moves

Ways to Teach It

  1. Give pairs sticky notes showing inputs and outputs, then have students reverse each pair and check whether any reversed inputs repeat.

  2. Ask students to explain why f(x) = x² fails on all real numbers but works when x is restricted to x ≥ 0.

  3. Run a card sort matching tables, graphs, and equations with labels reading inverse is a function or inverse is not a function.

  4. Compare Celsius conversion with a tossed ball's height over time, then decide which relationship can be reversed into a function.

Free download

Printable MA.912.F.3.6 Worksheet

Preview of the MA.912.F.3.6 printable worksheet

A ready-to-print activity worksheet aligned to MA.912.F.3.6, with an answer key for the teacher on its own page. No account needed.

PDF, US Letter, prints cleanly in black and white.

Download the worksheet

Keep exploring

Related Standards

Turn this exact standard into a lesson

Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.