@MISC{QUIN_1.MIZ,
  AUTHOR = {Popio{\l}ek, Jan},
  TITLE = {Quadratic Inequalities},
  DAY = {19},
  MONTH = {July},
  YEAR = {1991},
  ADDRESS1 = {Warsaw University\\Bia{\l}ystok},
  SUMMARY = {       Consider a quadratic trinomial of the form $P(x)=ax^2+bx+c$,
where $a\ne 0$.  The determinant of the equation $P(x)=0$ is of the form
 $\Delta(a,b,c)=b^2-4ac$. We prove several quadratic inequalities
when $\Delta(a,b,c)<0$, $\Delta(a,b,c)=0$ and $\Delta(a,b,c)>0$.}}

