2-8-2010The Quadratic FormulaThequadratic formulais a formual for finding the roots of a quadratic equation. It depends on aprocedure calledcompleting the square. Here’s the idea. Suppose you can do algebra to get your equationto look like this:(variable-stuff)2= (a number).Then you can solve for the variable-stuff by taking the square root of both sides.Example.Solve the equation forx.
Suppose you start out with a quadratic equation where youdon’thave a perfect square on one side.Suppose, for instance, that the variable-stuff isx2+ax.What would you need to add tox2+axto make it a perfect square?