ATan (arcus tangent)
  

Returns arctangent (value of angle of given tangens number).

syntax
ATan(tangens)

input
real number

returns
real number range:
- radian: <-Pi/2,Pi/2>
- degree: <-90,90>
- gradus: <-100,100>

example
ATan(1) = 45 when measure of angle is degree.