set of rational numbers | set of rational numbers Q

The doublestruck capital letter Q, Q, denotes the field of rationals. It derives from the German word Quotient, which can be translated as "ratio." The symbol Q first appeared in Bourbaki's Algèbre (reprinted as Bourbaki 1998, p. 671).

C | C^* | field of rationals | N | Q^_ | Q-function | Q^+ | q-product | q-series | R | Z