High Quality Content by WIKIPEDIA articles! A quadratic function, in mathematics, is a polynomial function of the form f(x)=ax^2+bx+c,quad a ne 0. The graph of a quadratic function is a parabola whose major axis is parallel to the y-axis. The expression ax2 + bx + c in the definition of a quadratic function is a polynomial of degree 2 or second order, or a 2nd degree polynomial, because the highest exponent of x is 2. If the quadratic function is set equal to zero, then the result is a quadratic equation. The solutions to the equation are called the roots of the equation.