﻿ ATN Function ---------------------------------------------------------------------------- Action Returns the arctangent of a numeric expression. Syntax ATN( numeric-expression) Remarks The argument numeric-expression can be of any numeric type. ATN (arctangent) is the inverse of TAN (tangent). ATN takes the ratio of two sides of a right triangle ( numeric-expression) and returns the corresponding angle. The ratio is the ratio of the lengths of the side opposite the angle and the side adjacent to the angle. The result is given in radians and is in the range --2 to --2 radians, where - = 3.141593 and --2 radians = 90 degrees. ATN is calculated in single precision if numeric-expression is an integer or single-precision value. If you use any other numeric data type, ATN is calculated in double precision. To convert values from degrees to radians, multiply the angle (in degrees) times --180 (or .0174532925199433). To convert a radian value to degrees, multiply it by 180-- (or 57.2957795130824). In both cases, - - 3.141593. See Also COS, SIN, TAN Example The following example first finds the tangent of PI-4 and then takes the arctangent of the value. The result is PI-4. CONST PI=3.141592653 PRINT ATN(TAN(PI-4.0)), PI-4.0 Output 78539816325 .78539816325