Light it up
http://illuminations.nctm.org/LessonDetail.aspx?ID=L606
A lesson plan for Grades 9–12 Algebra 1 and Algebra 2
In this cooperative learning activity, students are presented with a real-world problem: Given a mirror and laser pointer, determine the position where one should stand so that a reflected light image will hit a designated target. This investigation allows students to develop several rational functions that models three specific forms of a rational function. Students explore the relationship between the graph, the equation, and problem context. Illuminations provides an activity sheet, carousel cards, and detailed instructions for completing the lesson.
Students will:
- State the domain, range and end behavior of rational functions.
- Write rational functions that model problem situations.
- Use rational functions to solve problems.
NCTM Standards and Expectations:
- Generalize patterns using explicitly defined and recursively defined functions.
- Draw reasonable conclusions about a situation being modeled.
- Use symbolic algebra to represent and explain mathematical relationships.
North Carolina Curriculum Alignment
Mathematics (2004)
Grades 9–12 — Algebra 1
- Goal 1: Number and Operations - The learner will perform operations with numbers and expressions to solve problems.
- Objective 1.02: Use formulas and algebraic expressions, including iterative and recursive forms, to model and solve problems.
- Objective 1.03: Model and solve problems using direct variation
Grades 9–12 — Algebra 2
- Goal 2: Algebra - The learner will use relations and functions to solve problems.
- Objective 2.01: Use the composition and inverse of functions to model and solve problems; justify results.
- Objective 2.05: Use rational equations to model and solve problems; justify results.
- Solve using tables, graphs, and algebraic properties.
- Interpret the constants and coefficients in the context of the problem.
- Identify the asymptotes and intercepts graphically and algebraically.



