[ Arithmetic | Reference Manual | Alphabetic Index ]
# asin(+Number, -Result)

Evaluates the trigonometric function asin(Number) and unifies the resulting
value with Result.
*Number*
- A number.
*Result*
- Output: float.

## Description

This predicate is used by the ECLiPSe compiler to expand evaluable
arithmetic expressions. So the call to asin(Number, Result) is
equivalent to
Result is asin(Number)

which should be preferred for portability.
In coroutining mode, if Number is uninstantiated, the call to asin/2 is
delayed until this variable is instantiated.

### Modes and Determinism

### Exceptions

*(4) instantiation fault *
- Number is not instantiated (non-coroutining mode only).
*(24) number expected *
- Number is not of a numeric type.
*(20) arithmetic exception *
- Illegal arithmetic operation: Number is greater than 1 or less than -1.
*(141) unimplemented functionality *
- Argument is of type breal

## Examples

Success:
Result is asin(1.0). % gives Result = 1.5708
Result is asin(-0,5). % gives Result = -0.523599
Error:
Result is asin(2.0). % arithmetic exception

## See Also

is / 2