Node: ArcSin, Next: ArcTan, Previous: ArcCos, Up: Reference

### ArcSin

#### Synopsis

         function ArcSin (x: Real): Real;

or

         function ArcSin (z: Complex): Complex;

#### Description

`ArcSin` returns the (principal value of the) arcus sine of the argument. The result is in the range `-Pi / 2 < ArcSin (x) < Pi / 2` for real arguments.

#### Conforming to

`ArcSin` is a GNU Pascal extension.

#### Example

         program ArcSinDemo;
         begin
           { yields 3.14159 as ArcSin (0.5) = Pi / 6 }
           WriteLn (6 * ArcSin (0.5) : 0 : 5)
         end.

#### See also

ArcCos, ArcTan, Sin, Cos, Ln, Arg.