Question

What does quadratic functions mean

Answer 1

A quadratic function: f(x) = ax2 + bx + c
 A, b, and c are not equal to zero.
Graph of a quadratic function is a curve called a parabola. 

Answer 2

Quadratic functions are second-order equations of the form y=ax^2+bx+c.  Their graphs form parabolas. The defining characteristic of a quadratic is that the acceleration of the outputs is a constant.