## Algebra 2 (1st Edition)

An extraneous solution of an equation is a value obtained when solving for a specific variable but in the instant of plugging it in, it results in false equality. An example would be $\sqrt {x^2} = -1$. When squaring both sides, we get $x^2 = 1$ or $x=1,-1$. However when substituting, we see that $\sqrt 1 = -1$ which is false and thus is extraneous.