Returns the arccosine, or inverse cosine, of a number. The arccosine is the angle whose cosine is number. The returned angle is given in radians in the range 0 (zero) to pi.
Syntax
ACOS(number)
Number is the cosine of the angle you want and must be from -1 to 1.
Remark
If you want to convert the result from radians to degrees, multiply it by 180/PI() or use the DEGREES function.
Examples
| Formula | Description (Result) |
|---|---|
| =ACOS(-0.5) | Arccosine of -0.5 in radians, 2*pi/3 (2.094395) |
| =ACOS(-0.5)*180/PI() | Arccosine of -0.5 in degrees (120) |
| =DEGREES(ACOS(-0.5)) | Arccosine of -0.5 in degrees (120) |