# atan, atanh

## Purpose

Inverse tangent and inverse hyperbolic tangent.

## Synopsis

    Y = atan(X)
    Y = atanh(X)

## Description

`atan` and `atanh` operate element-wise on matrices. Their domains and ranges include complex values. All angles are in radians.

`atan(X)` returns the inverse tangent for each element of `X`. For real elements of `X` in the range [-1,1], `atan(x)` is in the range [-`pi`/4,`pi`/4]. `atan(X)` is always real.

`atanh(X)` returns the inverse hyperbolic tangent for each element of `X`.

## Examples

Graph the inverse tangent function for the range `-2 <= x <= 2`.

    x = -2:.05:2;
    plot(x, atan(x))

## Algorithm

## See Also

    atan2, cos, exp, funm, log, sin, sqrt, tan

(c) Copyright 1994 by The MathWorks, Inc.