Explain why the discriminant of a quadratic is useful.

The discriminant of a quadratic equation is useful because it provides information about the nature of the roots of the equation. Specifically, it tells us whether the roots are real or complex, and whether there are one, two, or no distinct roots. This information is important in various applications of quadratic equations, such as in solving problems related to optimization, physics, engineering, and finance. The discriminant can also be used to determine the number of solutions to a quadratic equation, which helps in determining the appropriate method of solving the equation. Overall, the discriminant provides insight into the behavior of a quadratic equation and is a valuable tool for solving problems involving such equations.