### Arc tangent Function in QTP

What is Atn Function :
Returns the arctangent of a number.
`Atn(number)`
The number argument can be any valid numeric expression.

#### Remarks

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.
The following example uses Atn to calculate the value of pi:
`Dim pi pi = 4 * `Atn(`1`)`   ' Calculate the value of pi.`
Note   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).

Some more relevant posts covering the VBScript functions and other Vbscript used for coding in QTP.: