ACOS Function In Excel To Return Inverse Cosine

In this tutorial, learn how to use the ACOS function to find the inverse of cosine of a number or cos inverse in excel. It returns an angle which you have to convert in degree using the below methods.

What is the ACOS Function in Excel

An ACOS function is the trigonometric function under the category Math/Trig of Excel. It is a built-in function of MS Excel you can use when you want to calculate the inverse of cosine.

acos function in excel to find inverse cosine in radian

You can find the inverse cosine angle with ACOS() using the methods given below. We can say that its result is cos inverse in excel

Syntax of ACOS Function

The syntax of the ACOS function is given below which contains a single argument.

Argument Passing to ACOS Function

There is only a single argument or parameter of the function to pass. See the description of the argument is given below.

Parameter Name Description
number The number is the value between -1 to 1 that you have to pass as an argument to get cos inverse in excel.

Now, let’s check the various examples to find the inverse cosine of a number.

Find Inverse Cosine of a Number to Get Cos Inverse in Excel

There are many examples given below to find the inverse cosine of value from -1 to 1.

Example 1

Output

1.047198

Example 2

acos function in excel to find inverse cosine in radian

The -1 number if pass as the argument will give the value of PI() as the output. The value of the PI is 3.141593 as given in the below example.

Output

3.141593

Example 3

Output

0

So, you have calculated the inverse cosine of any number between -1 to 1. The above outputs to get cos inverse in excel is in radian and not in degree. To convert them to a degree, you have to follow the method given in the next section. So, read further to find the required method.

How to Convert Radian to Degree

To convert radian to a degree, you have to multiply the inverse cosine value with the value 180/PI(). Check the below example to use and convert your output to a degree.

Example 1

Output

60

Example 2

find inverse cosine in degree

Output

180

Example 3

Output

0

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I hope you like this tutorial on how to use the ACOS function in Excel to get cos inverse in excel.

Reference
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