ACOS Function

Returns the arccosine of number, for example, the angle whose cosine is number.

Syntax

ACOS(number)

Remarks

The input value must be in the range -1 <= number <= 1, or a #NUM! error is returned. The resulting angle is in the range 0 <= angle <= PI radians (0 <= angle <= 180 degrees).

Example

ACOS(0)

Returns 90 deg