. . A Limit Process While computing the limits lim R x →α of certain functions R x ( ) , we may come across the following situations like, ∞ ∞ ×∞∞−∞ ∞ ∞ We say that they have the form of a number. But values cannot be assigned to them in a way that is consistent with the usual rules of addition and mutiplication of numbers.
We call these expressions indeterminate forms. Although they are not numbers, these indeterminate forms play a useful role in the limiting behaviour of a function. John (Johann) Bernoulli discovered a rule using derivatives to compute the limits of fractions whose numerators and denominators both approach zero or ¥ . The rule is known today as L’Hôpital’s Rule (pronounced as Lho pi tal Rule), named after Guillaume de l’Hospital’s, a French nobleman who wrote the earliest introductory differential calculus text, where the rule first appeared in print.