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IMARGUMENT Function
Summary
The Excel IMARGUMENT function extracts the angle (theta) in radians from a complex number, representing its argument in the complex plane. This engineering function is essential for complex number analysis, phase calculations, and mathematical computations involving polar forms.
Syntax
IMARGUMENT(inumber)Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
| inumber | Complex |
Yes | A complex number in 'real+imaginaryi' format or reference to COMPLEX function |
Using the IMARGUMENT Function
IMARGUMENT converts a complex number from rectangular form (a+bi) to its polar representation by returning the angle theta. Use it when you need phase angles, argument values, or when working with complex exponentials and trigonometric identities.
Common IMARGUMENT Examples
Basic IMARGUMENT Example
=IMARGUMENT("3+4i")Returns 0.92729522 radians (angle of complex number 3+4i)
Frequently Asked Questions
Common Errors and Solutions
#VALUE!
Cause: Invalid complex number format
Solution: Ensure proper 'a+bi' format or use COMPLEX function
#NUM!
Cause: Complex number is zero (undefined argument)
Solution: Verify the complex number is non-zero
Notes
- Returns radians, not degrees (multiply by 180/PI for degrees)
- Argument is undefined for zero complex numbers
- Works with positive and negative real/imaginary parts
Compatibility
Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365
Not available in: Excel 2003 and earlier
Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+