# ArcTrigonometricFunctionCategoryΒΆ

Category for the inverse trigonometric functions.

- acos: % -> %
`acos(x)`

returns the arc-cosine of`x`

. When evaluated into some subset of the complex numbers, one branch cut for acos lies along the negative real axis to the left of`-1`

(inclusive), continuous with the upper half plane, the other along the positive real axis to the right of 1 (inclusive), continuous with the lower half plane.

- acot: % -> %
`acot(x)`

returns the arc-cotangent of`x`

.

- acsc: % -> %
`acsc(x)`

returns the arc-cosecant of`x`

.

- asec: % -> %
`asec(x)`

returns the arc-secant of`x`

.

- asin: % -> %
`asin(x)`

returns the arc-sine of`x`

. When evaluated into some subset of the complex numbers, one branch cut for asin lies along the negative real axis to the left of`-1`

(inclusive), continuous with the upper half plane, the other along the positive real axis to the right of 1 (inclusive), continuous with the lower half plane.

- atan: % -> %
`atan(x)`

returns the arc-tangent of`x`

. When evaluated into some subset of the complex numbers, one branch cut for atan lies along the positive imaginary axis above %`i`

(exclusive), continuous with the left half plane, the other along the negative imaginary axis below -%`i`

(exclusive) continuous with the right half plane. The domain does not contain %`i`

and -%`i`

.