Lesson 7

Lesson 7: Solving Quadratic Equations by Factoring or Graphing

 

Focus

 

Parabolic reflectors, whose shape can be modelled by quadratic functions, often receive radio waves from outer space. In the Very Large Array, 27 radio antennas on rails sit on the Plains of San Agustin, 50 miles west of Socorro, New Mexico. Each antenna is 25 m (the height of an eight-storey building) in diameter and weighs 209 t (tonnes). The data from the antennas is combined electronically to give the resolution of an antenna 36 km across and the sensitivity of a dish 130 m in diameter.

 

As you progress through this lesson, you will analyze parabolic shapes in sports and communications. You will learn how to use the zeros of a quadratic function to solve corresponding equations and answer related problems.

 

Lesson Questions

 

This lesson will help you answer the following inquiry questions:

• How can you use a quadratic equation in factored form to solve problems involving the zeros of the corresponding quadratic function or the x-intercepts of the graph of the function?
  
  
• How can you find the roots of a quadratic equation by graphing the corresponding quadratic function?

Assessment

• Share 1
• Lesson 7 Assignment

All assessment items you encounter need to be placed in your course folder.

 

Save a copy of the Lesson 7 Assignment to your course folder. You will receive more information about how to complete the assignment later in this lesson.

 

Materials and Equipment

• graphing calculator