The acos function calculates the angle whose cosine is the specified number (the inverse operation of cos).

Syntax ​

acos( X )

Arguments ​

• X: A real number in range [-1, 1].

Results ​

The value of the arc cosine of X. Returns null if X < -1 or X > 1

Examples ​

This example returns 3.141592653589793:

print num = -1
| extend newField = acos( num )