Florida B.E.S.T. MA.912.AR.3.9

MathGrades 9–12Write, solve and graph quadratic equations, functions and inequalities in one and two variables.

The Standard

Given a mathematical or real-world context, write two-variable quadratic inequalities to represent relationships between quantities from a graph or a written description.

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

Teacher's field guide

What This Standard Means

What Students Need to Do

Students turn a parabolic boundary and a shaded region into an inequality using x and y. They also translate phrases such as above, below, at most, and including the boundary into inequality symbols.

What Mastery Looks Like

Given a graph, students identify the quadratic boundary and select <, ≤, >, or ≥ from the shading and boundary line. From a written context, they define variables, write the inequality, and check it with a reasonable point.

Common Misconceptions

Students may shade the wrong side or choose a strict inequality when the boundary should be included. They may write only an equation, or misread the parabola's shift, reflection, or width. In context problems, they may ignore limits on possible values.

How to Assess It

Exit ticket: A dashed parabola has equation y = (x - 2)² - 3, with the region below it shaded. Write the inequality and explain your symbol choice.

Lesson moves

Ways to Teach It

  1. Give students transparent coordinate grids to trace a parabola, test three points, and shade all points that satisfy a given inequality.

  2. Ask students to compare y < x² - 4 and y ≥ x² - 4, then explain how the boundary and shading change.

  3. Use matching cards with quadratic inequalities, shaded graphs, and test points, and have pairs justify each completed set.

  4. Model the space beneath a bridge arch from given measurements, then write an inequality showing where a vehicle could fit.

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Printable MA.912.AR.3.9 Worksheet

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