ACOS Function

Returns the arccosine of x.

enabled.

Usage

result = ACOS(x)

Input Parameters

x—The cosine of the desired angle. Cannot be of a complex data type and must be in the range –1 ≤ x ≤1.

Returned Value

result—Arccosine of x.

Keywords

None.

Discussion

The inverse cosine function, or arccosine, denoted by cos ^–1, is defined by:

y = cos –1x

if and only if:

cos y = x

where:

–1 ≤ x ≤ 1  and  0 ≤  y ≤  π

The parameter x can be an array, with the result having the same data type where each element contains the arccosine of the corresponding element from x.

When x is of double-precision floating-point data type, the result is of the same type. All other data types are converted to single-precision floating-point and yield a floating-point result. The result is an angle, expressed in radians, whose cosine is x.

Values generated by ACOS range between 0 and π.

Example

x = ACOS(1)
PRINT, x
; PV-WAVE prints: 0