## Quadratic Equations

A quadratic equation is a polynomial
equation of the second degree. The general form is

ax

^{2}+ bx + c = 0*a*≠ 0 (For

*a*= 0, the equation becomes a linear equation.)

The letters *a*, *b*,
and *c* are called coefficients: the quadratic
coefficient *a* is the coefficient of *x*^{2},
the linear coefficient *b* is the coefficient of *x*,
and *c* is the constant coefficient, also called the
free term or constant term.