The historical drama is a film genre in which stories are based more or less accurately upon historical events and famous persons. See also period piece[?].
... 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 ...