function Sin (x: Real): Real;
or
function Sin (z: Complex): Complex;
Sin returns the sine of the argument. The result is in the range -1 <= Sin (x) <= 1 for real arguments.
The function Sin is defined in ISO 7185 Pascal; its application to complex values is defined in ISO 10206 Extended Pascal.
program SinDemo; begin { yields 0.5 since Sin (Pi / 6) = 0.5 } WriteLn (Sin (Pi / 6) : 0 : 5) end.