Decades: 1340s 1350s 1360s 1370s 1380s - 1390s - 1400s 1410s 1420s 1430s 1440s
Years: 1389 1390 1391 1392 1393 - 1394 - 1395 1396 1397 1398 1399
Births
Deaths
... square roots of both sides yields <math>x+\frac{b}{2a}=\frac{\pm\sqrt{b^2-4ac}}{2a}.</math> Subtracting b/(2a) ...