What is COS function in Excel?
The COS function is one of the math functions of Excel.
It returns the cosine of an angle.
We can find this function in the Math&trig category of insert function Tab.
How to use COS function in excel
- Click on an empty cell (like F5 )

2. Click on the fx icon (or press shift+F3)

3. In the insert function tab you will see all functions

4. Select math and trig category
5. Select COS function
6. Then select ok

7. In the function arguments Tab you will see COS function
8. In the Number section you can enter the angle in radians for which you want the cosine
9. You will see results in formula result at the end of function arguments Tab

Examples of COS function in excel
Example 1:
How to use COS function in excel
You can see examples of COS function below:

cos(A2) ----->>>>answer is -1
cos(A3) ----->>>>answer is 0.707
cos(A4) ----->>>>answer is -1
cos(A5) ----->>>>answer is 0
cos(A6) ----->>>>answer is 1
What is the purpose of COS function?
It returns the cosine of an angle.
What is the Return value of COS function?
It returns a number.
How many arguments does COS function have?
This function has just 1 Argument.
The argument of COS function is number.
In the Number section you can enter the angle in radians for which you want the cosine
The argument of COS function is required and not optional.
COS(number) = number
Which version of excel supports COS function?
This function is available for all excel versions (2003-2019)