Decades: 1270s BC 1260s BC 1250s BC 1240s BC 1230s BC - 1220s BC - 1210s BC 1200s BC 1190s BC 1180s BC 1170s BC
Significant People
... The formula and its proof remain correct if the coefficients a, b and c are complex numbers, or more generally members of any field whose characteristic is not 2. ...