Purpose
Arccosine (inverse cosine) function.
Class
Elemental function
Argument type and attributes
- X
- must be of type real with a value that satisfies the inequality
|X| ≤ 1,
or be of type complex.
Result type and attributes
Same as X.
Result value
If X is of type real, the result value is as follows:
- It is expressed in radians, and approximates arccos(X).
- It is in the range 0 ≤ ACOS(X) ≤ PI.
If X is of type complex, the real part of the result value
is as follows:
- It is expressed in radians.
- It is in the range 0 ≤ REAL(ACOS(X)) ≤ PI.
Examples
ACOS(1.0) has the value 0.0.
ACOS((0.540302,
0.000000)) has the value (1.000000, 0.000000), approximately.
| Specific Name | Argument Type | Result Type | Pass As Arg? |
|---|---|---|---|
| ACOS | default real | default real | yes |
| DACOS | double precision real | double precision real | yes |
| QACOS 1 | REAL(16) | REAL(16) | yes |
| QARCOS 1 | REAL(16) | REAL(16) | yes |
Note:
- IBM Extension.