Let's review some of the main characteristics of the graph of a quadratic function. A quadratic function is nonlinear. Its values increase faster as |x| becomes greater, and it always has an axis of symmetry. These characteristics cause it to have a U-shape. This special graph is called a parabola.
This shape has special geometric properties that make it useful for many everyday devices, such as the famous parabolic antennas and the mirrors used in car lights.
