A quadratic function is a noun. The plural form would be quadratic functions.
"Hearty" can function as an adjective.
"Congregation" can function as a noun.
Function can be a noun and a verb. Noun: What something is used for. Verb: To have a function.
importance of function words in sentences
The word "assure" can function as a verb.
The word "cultivate" can function as a verb.
"Obvious" can function as an adjective.
The word "congregation" can function as a noun.
Squashed can function as a verb or an adjective.
The word "beach" can function as a noun.
The word "quick" can function as an adjective.
The word "conceive" can function as a verb.