Quote Originally Posted by Aerith's Knight View Post
one word: abc-equation

..

okay two words.

ax^2 + bx + c = 0

D = b^2 - 4ac

x = (b +/- sqrt(D)) / 2a


Works every time.
If you copy it down correctly. It should be

x = (-b+/-sqrt(b<sup>2</sup>-4ac))/2a

Gotta love the quadratic formula. It will always work. But make sure you are in standard form (ax<sup>2</sup>+bx+c=0) before completing the square, using synthetic division, factoring or use the quadratic formula.