Returns the arctangent of the specified value.
ATN(numeric_expression)
numeric_expression is the value for which you want to find the arctangent.
You can express an angle in either degrees or radians. ATN returns an angle in radians. To convert radians to degrees, use the following equation:
degrees = radians * (180/3.141593)
X = 3
PRINT ATN(X)
1.249046
Prints the arctangent of 3 radians (1.249046).