457. How many values of the quadratic function

$$
y=a x^{2}+b x+c
$$

must be given to determine this function? How can this question be formulated geometrically?
457. If for three different values of $x$ we know the corresponding values of $y$, then to determine $a, b, c$ we have a system of three equations. In other words: a parabola, whose axis is parallel to $0 y$, represented by the equation $y=a x^{2}+b x+c$, is defined by three points lying on it.