In this tutorial you will learn how to use the Atn Function.
The Atn function returns a Double specifying the arctangent of an angle.
=Atn( number )
number any valid number expression that expresses an angle in radians
The Atn function takes the ratio of two sides of a right triangle (number) and returns the corresponding angle in radians. The ratio is the length of the side opposite the angle divided by the length of the side adjacent to the angle.
The range of the result is pi/2 to pi/2 radians.
To convert degrees to radians, multiply degrees by pi/180. To convert radians to degrees, multiply radians by 180/pi.
Atn is the inverse trigonometric function of Tan, which takes an angle as its argument and returns the ratio of two sides of a right triangle. Do not confuse Atn with the cotangent, which is the simple inverse of a tangent (1/tangent).
In this example we will use 1.
The result is 0.785398163397448.
Query
The results using a Query would be
SELECT Atn(1);
FORM
In a Form you could set the Default Value of a Textbox to
=Atn(1)
VBA
In a Form add a TEXTBOX control and rename it "txtAtn", then you could add the following in the Load Event.