External link
Park Service biography (http://www.nps.gov/jeff/LewisClark2/Circa1804/WestwardExpansion/EarlyExplorers/ZebulonPike.htm)
... from both sides, we get <math>x=\frac{-b}{2a}\pm\frac{\sqrt{b^2-4ac}}{2a}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}.</math> Generalizations The formula and ...