A quadratic function is a polynomial function in the form The graph of a quadratic function is a parabola. If , the function becomes linear. is a second degree polynomial, as the highest exponent of is 2. When the function is set to equal zero, it is called a quadratic equation. The solutions to the equation, called roots (zeros) correspond to x-intercepts on a graph. They can be found by factoring, completing the square, graphing, or the quadratic formula.