﻿ ACOS function

# ACOS function

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.

Example

The example may be easier to understand if you copy it to a blank worksheet.

How to copy an example

1. Create a blank workbook or worksheet.

2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help

3. Press CTRL+C.

4. In the worksheet, select cell A1, and press CTRL+V.

5. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

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 A B 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)

Applies To: Excel 2007

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