VBA Atn – Find Arctangent and Inverse Tangent of Number

To find the arctangent, or inverse tangent, of a number in VBA, we can use the VBA Atn() function.

Atn(x)

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.

To find the arctangent of a number, we use the VBA Atn() function.

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

Atn(x)

The input to the Atn() function must be a double. The return value will be a double between -pi/2 and pi/2 radians.

Debug.Print Atn(0.5)
Debug.Print Atn(0)
Debug.Print Atn(-0.75)

'Output
0.5235987755982989
0.0
-0.848062078981481

Finding the Inverse Tangent of a Number in VBA

Arctangent is defined as the inverse of the tangent of a number.

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

Debug.Print Atn(Tan(WorksheetFunction.Pi/3))
Debug.Print WorksheetFunction.Pi/3

'Output:
1.0471975511965976
1.0471975511965976

Find Arc Tangent of the Quotient of Two Arguments with Atan2() in VBA

VBA gives us the ability to find the arctangent of the quotient of two numbers, where the two numbers represents the coordinates of a point (x,y). To find the arctangent of a the quotient of two numbers, we use the atan2() Worksheet Function.

Below is the VBA syntax to find the inverse tangent of the quotient of two numbers.

WorksheetFunction.Atan2(x)

The inputs to the Atan2() function must be a doubles. The return value will be a numeric value between -pi and pi.

Debug.Print WorksheetFunction.Atan2(5,1)
Debug.Print WorksheetFunction.Atan2(0,1)
Debug.Print WorksheetFunction.Atan2(-3,7)

'Output:
1.373400766945016
0.0
-0.40489178628508343

Hopefully this article has been beneficial for you to understand how to use the VBA Atn() function to find the arctangent of a number.