What do you use a quadratic equation for?

A quadratic equation is used to model situations where a variable's relationship with another variable produces a parabolic shape, such as projectile motion, optimizing area or profit, and analyzing certain economic trends. It is often applied in physics to determine the trajectory of objects, in finance to calculate maximum profit points, and in various engineering problems. Additionally, quadratic equations can be used to find the roots of functions, which can help identify key points in graphs.