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ExcelImargumentFunction
The Excel IMARGUMENT Function
Basic Description
The Excel IMARGUMENT function returns the
argument
θ, (an angle expressed in radians), of a supplied complex number.
θ is the angle that satisfies the following equation:
The syntax of the Imargument function is :
IMARGUMENT( inumber )
where the inumber argument is a complex number.
Excel Imargument Function Examples
The spreadsheet below shows examples of the Excel Imargument function, used find the angle θ, of
several complex numbers. For each of the examples, the complex numbers are supplied to the function in
different ways.
The spreadsheet on the left shows the formulas and the spreadsheet on the right shows the results.
Formulas:

A 
B 
1 
5+2i 
=IMARGUMENT( A1 ) 
2 

=IMARGUMENT( "2i" ) 
3 

=IMARGUMENT( 6 ) 
4 

=IMARGUMENT( "3i" ) 
5 

=IMARGUMENT( COMPLEX( 4, 1 ) ) 

Results:

A 
B 
1 
5+2i 
0.380506377 
2 

0.463647609 
3 

0 
4 

1.570796327 
5 

0.244978663 

Further information on the Excel Imargument function can be found on the
Microsoft Office website.
Imargument Function Errors
If you get an error from the Excel Imargument Function, this is likely to be one of the following:
Common Errors
#NUM!



Occurs if the supplied inumber argument is not recognised as a complex number

#NAME?



Occurs when Analysis ToolPak addin is not enabled in your Excel.
You will need to enable the addin if you want to use the Excel complex number functions.
+ Show How to Do This in Excel 2003:
 From the Tools dropdown menu, select the option AddIns ...
 An 'AddIns' window will pop up. From this, select the option Analysis ToolPak and click OK
+ Show How to Do This in Excel 2007:
 Click the Microsoft button on the top left of your spreadsheet and select
the Excel Options button
 From the menu on the left hand side, select AddIns
 In the 'Manage:' box, select Excel Addins and click Go...
 An 'AddIns' window will pop up. From this, select the option Analysis ToolPak and click OK
+ Show How to Do This in Excel 2010:
 Click the File tab (top left of your spreadsheet) and select Options
 From the menu on the left hand side, select AddIns
 If the window that pops up doesn't show the 'Addins' list, use the 'Manage:'
dropdown menu (at the bottom of the window) to select Excel Addins. Click Go...
 From the 'AddIns' window, select the option Analysis ToolPak and click OK
