# ASIN()

Arcus sine of the argument

Syntax

  ASIN (nSine) -> nRadiant

Arguments

  <nSine> the sine of an angle

Returns

  <nRadiant> the angle whose sine is <nSine>

Description

  The function ASIN() is the inverse function of SIN(). It takes a sine value and returns the smallest(!) angle whose sine equals to the argument. The return value is given in radiants (full angle equals 2*Pi - see DTOR() if you need to convert it into degress). Note, that <nSine> must be between -1 and 1 and that <nRadiant> is always between -PI()/2 and PI()/2.

Examples

          ? asin (0.0) --> 0.0
          ? asin (0.5) --> 0.5235...
    Tests
          asin (0.0) == 0.0
          asin (sqrt(1/2)) == PI()/4
          asin (1.0) == PI()/2
          asin (0.0) == 0.0  // and not PI(), since the smallest angle is returned !

Status

  Ready

Compliance

  ASIN() is compatible with CT3's ASIN().

Platforms

  All

Files

  Source is trig.c, library is libct.

See Also

- SIN()
- COS()
- TAN()
- COT()
- ACOS()
- ATAN()
- ATN2()
- SINH()
- COSH()
- TANH()
- RTOD()
- DTOR()
- PI()