3.5.1.2.1 acos

Description

The acos(x) function returns the inverse of the corresponding trigonometric function. x must be within -1 and 1 for acos, or a missing value is returned. Returned values are in radians, degrees or gradians, depending upon the system.math.angularunits object property (which can also be set in the Options dialog box).

Syntax

double acos(double x)

Parameter

x

is the value you want to get arccosine of. It must be in [-1, 1].

Return

Returns the inverse of the corresponding trigonometric function.

Example

aa = acos(1);
aa = ; //should return 0.