| The Columbia Encyclopedia, Sixth Edition. 2001-07. |
| |
| quadratic |
| |
| |
| mathematical expression of the second degree in one or more unknowns (see polynomial). The general quadratic in one unknown has the form ax2+bx+c, where a, b, and c are constants and x is the variable. A quadratic equation ax2+bx+c=0 always has two roots, not necessarily distinct; these may be real or complex (see number). The quadratic formulagives the roots of any quadratic equation in terms of its coefficients a, b, and c. The expression b2-4ac is called the discriminant and vanishes when the two roots coincide. If a, b, and c are real and the discriminant is not less than zero, the roots are real. |
| |
| | | The Columbia Encyclopedia, Sixth Edition. Copyright © 2007 Columbia University Press. |
|
|
