Extraneous roots are an unsolved mystery for our freshmen level college math students. The students are often confused and wonder what extraneous roots are and how do they suddenly appear while solving an algebraic equation. In this paper we clarify the idea of extraneous roots and connect the algebra and geometry behind extraneous roots.
Goel, Sudhir and Iwan Elstak
"Connecting Algebra and Geometry for Extraneous Roots,"
Georgia Journal of Science, Vol. 71, No. 2, Article 11.
Available at: http://digitalcommons.gaacademy.org/gjs/vol71/iss2/11