Skip to content

ATAN function ​

Overview ​

ATAN is a function of the Math and Trigonometry category that calculates the inverse tangent (arctangent) of a number, returning an angle in the range [-π/2 to +π/2], expressed in radians.

Usage ​

Syntax ​

ATAN (number) => atan

Argument descriptions ​

  • number (number, required). The number whose arctangent is to be calculated, in the range [-∞, +∞].

Additional guidance ​

None.

Returned value ​

ATAN returns a number in radians in the range [-π/2 to +π/2] that is the angle whose tangent is the specified number.

Error conditions ​

  • In common with many other IronCalc functions, ATAN propagates errors that are found in its argument.
  • If no argument, or more than one argument, is supplied, then ATAN returns the #ERROR! error.
  • If the value of the number argument is not (or cannot be converted to) a number, then ATAN returns the #VALUE! error.
  • For some argument values, ATAN may return a #DIV/0! error.
  • For more information about the different types of errors that you may encounter when using IronCalc functions, visit our Error Types page.

Details ​

  • The ATAN function utilizes the atan() method provided by the Rust Standard Library.
  • The figure below illustrates the output of the ATAN function for angles x in the range [-∞, +∞].

Examples ​