| 释义 |
extremum Math.|ɛkˈstriːməm|
Pl. extrema, extremums.
[a. L. extrēmum, neut. of extrēmus (see extreme a., adv., and n.). First used as a mathematical term (in German) by P. du Bois-Reymond 1879, in Math. Ann. XV. 564.]
A value of a function that is a maximum or a minimum (either relative or absolute).
1904O. Bolza Lect. Calculus Variations i. 10 The word ‘extremum’ will be used for maximum and minimum alike, when it is not necessary to distinguish between them. 1947Courant & Robbins What is Math.? (ed. 4) vii. 343 A point where the derivative vanishes, whether it is an extremum or not, is called a stationary point. 1962A. H. Frink tr. Akhiezer's Calculus of Variations i. 5 An extremum in the whole collection M is called an absolute extremum. We shall also consider relative extrema; to define them we must introduce the notion of neighbourhood. 1968M. J. Forray Variational Calculus in Sci. & Engin. i. 6 Are f(4/5) = 44/55 and f(0) = 0 the absolute maximum and minimum for f(x) [= x4 - x5] in -2 {slle} x {slle} 2? We know that these extremums exist for a continuous function defined over a closed interval. |