Education Technology

Algebra II: Extraneous Solutions

by Texas Instruments


  • Students will determine the solution of radical equations both algebraically and geometrically.
  • Students will know why solutions to radical equations should be checked by algebraic solution for extraneous solutions.
  • Students will establish the relationship between real and nonreal number solutions for radical equations.
  • Students will be able to explain why squaring both sides of an equation can lead to extraneous solutions.


  • radical equations
  • real numbers
  • extraneous solutions

About the Lesson

This lesson allows students to discover solutions of radical equations and investigate extraneous solutions. As a result, students will:

  • Solve radical equations using handheld graphing technology.
  • Solve radical equations using algebra and test the validity of the solution.
  • Justify the solution(s) of a radical equation.