Толковый словарь английского языка - l'hopital's rule

or L'Hospital's rule noun Etymology: Guillaume de l'Hôpital died 1704 French mathematician Date: 1944 a theorem in calculus: if at a given point two functions have an infinite limit or zero as a limit and are both differentiable in a neighborhood of this point then the limit of the quotient of the functions is equal to the limit of the quotient of their derivatives provided that this limit exists