101 uses of a quadratic equation: Part II
In 101 uses of a quadratic equation: Part I in issue 29 of Plus we took a look at quadratic equations and saw how they arose naturally in various simple problems. In this second part we continue our journey. We shall soon see how the humble quadratic makes its appearance in many different and important applications.
Let us begin where we left off, with the quadratic curves known as the circle, ellipse, hyperbola and parabola. These were known and have been studied since the ancient Greeks, but apart from the circle they did not seem to have any practical application. However, in the 16th century the time came for them to change the world.
