In classical geometry, a point is an entity that has no extent.
In the modern set theoretic approach to topology, this is formalised as: a point in a spaceX is simply an element of the set X.
... equation
<math>ax^2+bx+c=0</math>
in terms of the coefficients a, b and c, which are assumed to be real (but see below for generalizations) with a being ...