versed sine

Historically, the versed sine was considered one of the most important trigonometric functions.

By careful measurements with dynamometers he validated his theory that a versed sine wave produces the ideal shape.

The versine or versed sine is a trigonometric function already appearing in some of the earliest trigonometric tables.

On the other hand, the versed sine of θ is the distance CD from the center of the chord to the center of the arc.

The convex surface of any segment of a sphere is, to the entire surface of the sphere itself, as the versed sine of the segment to the diameter of the sphere.

In further keeping with the interpretation of the sine as "vertical" and the versed sine as "horizontal", sagitta is also an obsolete synonym for the abscissa (the horizontal axis of a graph).