# Quadratic equation

### From Conservapedia

A **quadratic equation** can take two forms. The general formula, written as a function of *x*, *y* = *f*(*x*), is:

*y*=*a**x*^{2}+*b**x*+*c*

The graph of a quadratic equation is a parabola, one of the conic sections. (In some cases, the parabola collapses, most obviously when *a* = 0)

The points where this curve crosses the x axis are represented by the second form of the equation:

*a**x*^{2}+*b**x*+*c*= 0

These are solved for using the quadratic formula, which will not only solve for real roots, but result in the imaginary roots if the parabola does not actually cross the y axis (this is when 4*a**c* is greater than *b*^{2}).

Quadratic equations are very important in calculating the motion of bodies under constant acceleration, i.e., gravity (when close to the earth's surface).

The derivative of a quadratic equation is a simple linear function: