Formulei

Formulei is the genitive and dative singular form of the Romanian noun formulă, which means "formula." It is used to indicate possession or to mark the indirect object in clauses that refer to a formula. For example, cartea formulei translates to "the formula's book," and rezultatul formulei means "the result of the formula." In Romanian grammar, formulă is a feminine noun of the first declension, and formulei is its singular genitive/dative form.

The term derives from Latin formula and the French formelle, reflecting historical influences on Romanian scientific and mathematical vocabulary. In contemporary usage, formulei appears primarily in technical or academic prose when a specific formula is being discussed, though the base form formulă remains common for referring to the general concept of a formula. The exact properties of the form—genitive versus dative—depend on the syntactic role the noun phrase plays in a sentence.

See also formulă, the basic noun meaning "formula," and related terms in other Romance languages that share a common etymological root.