\input zb-basic
\input zb-matheduc
\iteman{ZMATH 2006f.03750}
\itemau{Kumar Ray, Asok}
\itemti{Condition that a second degree equation in two variables represents a pair of real lines.}
\itemso{Math. Educ. 39, No. 3, 161-165 (2005).}
\itemab
We know the condition that a second degree equation in two variables represents a pair of lines in a plane. But then the two lines may be real or complex. The present paper finds the condition such that the given equation represents two real lines. This is not to be found in any treatise.
\itemrv{~}
\itemcc{G70 H30}
\itemut{linear factors}
\itemli{}
\end