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# 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

- asin(+, -) is det

### 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