radians Algorithm

The radian is the SI unit for measure angles, and is the standard unit of angular measure used in many areas of mathematics. The length of an arc of a unit circle is numerically equal to the measurement in radians of the angle that it subtends; one radian is exactly under 57.3 degrees (expansion at OEIS: A072097). The concept of radian measure, as opposed to the degree of an angle, is normally credited to Roger Cotes in 1714.The term radian first looked in print on 5 June 1873, in examination questions put by James Thomson (brother of lord Kelvin) at Queen's College, Belfast. He described the radian in everything but name, and he recognized its naturalness as a unit of angular measure.

radians source code, pseudocode and analysis