trigonometric function

noun

1

: a function (such as the sine, cosine, tangent, cotangent, secant, or cosecant) of an arc or angle most simply expressed in terms of the ratios of pairs of sides of a right-angled triangle

called also circular function

2

: the inverse (such as the arcsine, arccosine, or arctangent) of a trigonometric function

Examples of trigonometric function in a Sentence

Recent Examples on the Web

The unsatisfying answer is that somewhere in the probability calculation there is an infinite sum that happens to correspond to the values of the arcsin function—a trigonometric function closely related to pi. —Emma R. Hasson, Scientific American, 12 Mar. 2026

Illustration: Rhett Allain This solution includes the trigonometric function cosine. —Rhett Allain, WIRED, 14 Mar. 2023

Spacecraft software demands sophisticated mathematical programming, full of matrix operations, trigonometric functions, and multiple precision variables. —Frank O’Brien, Ars Technica, 30 Jan. 2020

Word History

First Known Use

1909, in the meaning defined at sense 1

Rhymes for trigonometric function

• adjunction
• compunction
• conjunction
• disjunction
• dysfunction
• injunction
• inunction
• malfunction
• eigenfunction
• multifunction
• heterojunction
• junction

Kids Definition

trigonometric function

noun

: any of a group of functions (as the sine, cosine, and tangent) that for an acute angle are most easily expressed as ratios between the sides of a right triangle containing the angle