Main Page | See live article | Alphabetical index Completing the square is a technique of elementary algebra wherein an expression is replaced by one of the form Specifically, we have See quadratic formula for the application to the problem of solving the quadratic equation. Example Consider the problem of finding this antiderivative: The denominator is Adding (10/2)2 = 25 to x2 - 10x gives a perfect square x2 - 10x + 25 = (x - 5)2. So we get Our integral becomes Completing the square reduces any problem involving a quadratic polynomial to one involving a quadractic polynomial with no 1st-degree term. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.