# How do you find extraneous solutions when solving radical equations?

##### 1 Answer

Jan 15, 2015

Let's start with an equation.

This can be solved easily by:

but wait! we have to be careful whenever we square both sides of an equation.

Re-substitute the two answers into the original equation.

That's fine, one more.

Our extraneous answer is

To find the extraneous answer of any equation, just find the solutions and then re-substitute the solutions into the original equation. The answer that results in an illogical equation is the extraneous answer.