ACOS

**Syntax:** **ACOS( X)**

*X* = a numeric value between -1 and 1.

**ACOS** returns the arc cosine of angle *X*. The result is
the angle (in radians) whose cosine is *X* and ranges from
0 to . To convert the result from radians to degrees,
use the **DEGREES** function.

**Examples:**

**ACOS**(1) = 0

**ACOS**(R3) = 1.670963748, where R3 = -0.1

**DEGREES**(**ACOS**(0)) = 90

**ACOS**(-20) = Error - **ACOS**, domain is -1 = x = 1

**Excel function:** ACOS

Grey Trout Software

02 March 2003