Extreme Value Theorem - History

History

The extreme value theorem was originally proven by Bernard Bolzano in the 1830s in a work Function Theory but the work remained unpublished until 1930. Bolzano's proof consisted of showing that a continuous function on a closed interval was bounded, and then showing that the function attained its maximum and minimum value. Both proofs involved what is known today as the Bolzano–Weierstrass theorem (Rusnock & Kerr-Lawson 2005). The result was also discovered later by Weierstrass in 1860.