ACOS Function

Returns the arc-cosine of x.

result = ACOS(x)

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

result Arc-cosine of x.

None.

The inverse cosine function, or arc-cosine, denoted by cos ^-1, is defined by:

y = cos ^-1x

if and only if

cos y = x

where

-1 x 1 and 0 y

The parameter x can be an array, with the result having the same data type where each element contains the arc-cosine 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 .

x = ACOS(1)
PRINT, x

COS

For a list of other transcendental functions, see Chapter 1, Functional Summary of Routines.