Cos-1

Cos-1, COS-1, cos-1, or cos&minus;1 may refer to:


 * Cos-1, one of two commonly used COS cell lines
 * cos x&minus;1 = cos(x)&minus;1 = &minus;(1&minus;cos(x)) = &minus;ver(x) or negative versine of x, the additive inverse (or negation) of an old trigonometric function
 * cos&minus;1y = cos&minus;1(y), sometimes interpreted as arccos(y) or arccosine of y, the compositional inverse of the trigonometric function cosine (see below for ambiguity)
 * cos&minus;1x = cos&minus;1(x), sometimes interpreted as (cos(x))&minus;1 = $1⁄cos(x)$ = sec(x) or secant of x, the multiplicative inverse (or reciprocal) of the trigonometric function cosine (see above for ambiguity)
 * cos x&minus;1, sometimes interpreted as cos(x&minus;1) = cos($1⁄x$), the cosine of the multiplicative inverse (or reciprocal) of x (see below for ambiguity)
 * cos x&minus;1, sometimes interpreted as (cos(x))&minus;1 = $1⁄cos(x)$ = sec(x) or secant of x, the multiplicative inverse (or reciprocal) of the trigonometric function cosine (see above for ambiguity)