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EXTRANEOUS SOLUTION

Extraneous Solution

Definition Of Extraneous Solution

Extraneous Solution is a solution of the simplified form of an equation that does not satisfy the original equation.

Video Examples: Extraneous solution when solving radical equations
 

Example of Extraneous Solution

Consider the equation  example of   Extraneous Solution  . 
Squaring both sides and solving the equation for y, we get, y = 1, 25.
Check that only y = 25 satisfies the original equation, not y = 1. So, y = 1 is an extraneous solution. 

Solved Example on Extraneous Solution

Ques: Solve  example of   Extraneous Solution  and check whether the solution is extraneous.

Choices:

A. Yes
B. No
Correct Answer: B

Solution:

Step 1: example of   Extraneous Solution  
Step 2:  example   Extraneous Solution  
Step 3:  examples of   Extraneous Solution  
Step 4: x = 144 
Step 5: Substitute the value of x in the original equation. 
 define Extraneous Solution  so, x = 144 is an extraneous solution.

Quick Summary

  • Extraneous solutions can occur when solving radical equations or equations involving rational expressions.
  • Always check your solutions by substituting them back into the original equation.
  • If a solution does not satisfy the original equation, it is an extraneous solution and should be discarded.
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🍎 Teacher Insights

Emphasize the importance of checking solutions in the original equation to avoid accepting extraneous solutions. Provide plenty of examples where extraneous solutions arise and demonstrate the substitution process clearly.

🎓 Prerequisites

  • Solving equations
  • Radical equations
  • Substitution
  • Basic algebra skills

Check Your Knowledge

Q1: Solve for x: sqrt(x + 3) = x - 3

Q2: Which of the following operations is most likely to introduce extraneous solutions?

Frequently Asked Questions

Q: Why do extraneous solutions occur?
A: Extraneous solutions occur because certain operations, such as squaring both sides of an equation, can introduce solutions that do not satisfy the original equation. This happens because the operation is not reversible for all values.

Q: How do I identify an extraneous solution?
A: To identify an extraneous solution, substitute each solution you obtain back into the original equation. If the solution does not make the original equation true, it is an extraneous solution.

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