# ATAN()

Arcus tangent of the argument

Syntax

  ACOS (nTangent) -> nRadiant

Arguments

  <nTangent> the tangent of an angle

Returns

  <nRadiant> the angle whose tangent is <nTangent>

Description

  The function ATAN() is the inverse function of TAN(). It takes a tangent value and returns the smallest(!) angle whose tangent equals to the argument. The return value is given in radiants between -PI()/2 and PI()/2 (full angle equals 2*Pi - see DTOR() if you need to convert it into degress).

Examples

          ? atan (0.0) --> 0.0
          ? atan (0.5) --> 0.4636...
    Tests
          atan (0.0) == 0.0
          atan (1.0) == PI()/4
          atan (0.0) == 0.0 // and not PI(), although tan (PI()) == 0.0 !

Status

  Ready

Compliance

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

Platforms

  All

Files

  Source is trig.c, library is libct.

See Also

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