Quadratic formula
Revision as of 23:09, 31 October 2006 by I_like_pie (talk | contribs)
The quadratic formula is a general expression for the solutions to a quadratic equation.
General Solution For A Quadratic by Completing the Square
Let the quadratic be in the form .
Moving c to the other side, we obtain
Dividing by and adding
to both sides yields
.
Factoring the LHS gives
As described above, an equation in this form can be solved, yielding
This formula is also called the quadratic formula.
Given the values , we can find all real and complex solutions to the quadratic equation.
Variation
In some situations, it is preferable to use this variation of the quadratic formula: