# IMARGUMENT

## Content

This function returns the argument theta, which is an angle expressed in radians.

## Syntax

`IMARGUMENT(complexnum)`

## Arguments

The *complexnum* argument is a complex number for which to return the argument theta.

## Remarks

An error is returned if the *complexnum* argument is not in the form "x+yi" or "x+yj". For more information, refer to [Complex Numbers](/spreadjs/docs/v16/formulareference/formulaoverview/functionsformula/complexnumbers).

## Data Types

Accepts number and string data. Returns number data.

## Examples

`IMARGUMENT("3+5j")`