Noun
the calculus of maxima and minima of definite integrals
Source: WordNetWe may also mention his essay on the calculus of variations (Mem. de l'acad., 1833), and his memoirs on the probability of the mean results of observations (Connaiss. d. temps, 1827, &c). Source: Internet
Noether's theorem has become a fundamental tool of modern theoretical physics and the calculus of variations. Source: Internet
This surface is called a minimal surface and it, too, can be found using the calculus of variations. Source: Internet