ArcTan (ATan)

This function is available only in the Formula Toolbox.

ArcTan expresses the tangent function in radians between 0 and pi. For example, the ArcTan of 1 equals pi/4.

The tangent function takes the selected chart value, converts it into radians, and calculates a tangent value. ArcTan relates only to the right half of the unit circle.

This value is calculated as follows:

1090/(2*pi) = 173.478                           Calculates the laps around the unit circle

.478 * (2*pi) = 3.00894                         Takes the leftover lap and converts it to radians

Sin(3.00894) radians = .132263954          Calculates the sine for the calculated radians

Cos(3.00894) radians = -.991214531        Calculates the cosine for the calculated radians

.13226249/.991214531 = -.1334             Divides the sine by the cosine

Therefore,

ArcTan(-.1334) = -.13264826 + pi = 3.00894 radians

Example: ATan(@)