Fortifications are militaryconstructions designed for defensivewarfare. They have been used for many thousands of years, in a variety of increasingly complex designs. The practice of improving an area's defense is also known as "fortification". Many military installations are known as forts, although they are not always "fortified".
... both of which are real. (Geometrically, this means that the parabola intersects the x-axis in two points.)
If the discriminant is negative, then there are two different ...