Centuries: 4th century - 5th century - 6th century
Decades: 380s 390s 400s 410s 420s - 430s - 440s 450s 460s 470s 480s
Years: 428 429 430 431 432 - 433 - 434 435 436 437 438
Births
Deaths
... x to the quadratic equation <math>ax^2+bx+c=0</math> in terms of the coefficients a, b and c, which are assumed to be real (but see below fo ...