Question

What are dense rational numbers

Answer 1

Informally, for every point in X, the point is either in A or arbitrarily "close" to a member of A — for instance, the rational numbers are a dense subset of the real numbers because every real number either is a rational number or has a rational number arbitrarily close to it (see Diophantine approximation).

Answer 2

The rational numbers are a dense subset of the real numbers because every real number either is a rational number or has a rational number arbitrarily close to it.