Decades: 1150s 1160s 1170s 1180s 1190s - 1200s - 1210s 1220s 1230s 1240s 1250s
Years: 1198 1199 1200 1201 1202 - 1203 - 1204 1205 1206 1207 1208
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... both sides, we get <math>x=\frac{-b}{2a}\pm\frac{\sqrt{b^2-4ac}}{2a}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}.</math> Generalizations The formula and its ...