Suppose that f(x) → 0 and g(x) → 0 as x → a. Then the limit of the quotient f(x)/g(x) as x → a is said to give an indeterminate form, sometimes denoted by 0/0. It may be that a specific limit f(x)/g(x) can nevertheless be found by some method such as L’Hôpital’s rule.

Other indeterminate forms are ∞/∞, ∞ – ∞, 0×∞, 0⁰, 1^∞, ∞⁰. In general, these forms cannot be given definite values but in some contexts have an understood value; for example setting x = 0 in the polynomial $f\left(x\right)={\sum }_0^n{a}_k{x}^k$ to give f(0) = a₀ assigns 0⁰ the value 1.