Navigation:  Formulas and functions > Functions from A to Z > ACOS (arccosine)

Syntax:

ACOS(number)

Description:

The ACOS function (arccosine) is the inverse function of the COS function: It returns the inverse cosine of a number – that is, the angle whose cosine is the number.

Number must lie within the range from -1 to 1.

The result is expressed in radians.

Example:

ACOS(1) returns 0

ACOS(COS(0.1234)) returns 0.1234

Tip:

You can use the DEGREES function to convert the result from radians to degrees.

See also:

COS, ASIN, ATAN