To find the arccosine, or inverse cosine, of a number in VBA, we can use the Excel worksheet function Acos().


In VBA, we can easily use trigonometric functions from the collection of VBA math functions. These VBA math functions allow us to perform trigonometry easily.

Unfortunately, there is not a function in VBA to calculate the arccosine of a number.

To find the arccosine of a number, we use the Excel worksheet function acos().

Below is the VBA syntax to find the inverse cosine of a number.


The input to the Acos() function must be a double between -1 and 1. The return value will be a double between 0 and pi radians.

Debug.Print WorksheetFunction.Acos(0.5)
Debug.Print WorksheetFunction.Acos(0)
Debug.Print WorksheetFunction.Acos(-0.75)


Finding the Inverse Cosine of a Number in VBA

Arccosine is defined as the inverse of the cosine of a number.

Below, we show that if we pass a number to Cos() and then call the Excel Acos() worksheet function, we get back the same number.

Debug.Print WorksheetFunction.Acos(Cos(WorksheetFunction.Pi/3))
Debug.Print WorksheetFunction.Pi/3


Hopefully this article has been beneficial for you to understand how to use the Excel Acos() worksheet function in VBA to find the arccosine of a number.

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Last Update: February 26, 2024