Decades: 50s BC 40s BC 30s BC 20s BC 10s BC - 0s BC - 0s 10s 20s 30s 40s
8 BC7 BC 6 BC 5 BC 4 BC 3 BC 2 BC 1 BC 1 2 3
Births
Deaths
... be understood as "either of those element(s) of the field whose square equals b2 - 4ac". In some fields, some elements have no square roots and some have two; only zero ...