# ACOS Function

The ACOS function is one of the math and trigonometry functions. It is used to return the arccosine of a number.

The ACOS function syntax is:

ACOS(x)

where x is the cosine of the angle you wish to find, a numeric value greater than or equal to -1 but less than or equal to 1 entered manually or included into the cell you make reference to.

To apply the ACOS function,

1. select the cell where you wish to display the result,
2. click the Insert function icon situated at the top toolbar,
   or right-click within a selected cell and select the Insert Function option from the menu,
   or click the icon situated at the formula bar,
3. select the Math and trigonometry function group from the list,
4. click the ACOS function,
5. enter the required argument,
6. press the Enter button.

The result will be displayed in the selected cell.