# The Excel IMREAL Function

Related Function:
IMAGINARY Function
Complex Numbers

Within the world of complex numbers, the 'imaginary' value, i is used to represent the square root of -1.

A Complex Number is composed of a real number combined with an imaginary number.

E.g. The complex number, z, is written as

z   =   5 + 2i

## Basic Description

The Excel IMREAL function returns the real coefficient of a supplied complex number

- i.e. the function returns the value a, for the complex number a + bi.

The format of the Imreal function is :

IMREAL( inumber )

where the inumber argument is a Complex Number.

Note that complex numbers are simply stored as text in Excel. When a text string in the format "a+bi" or "a+bj" is supplied to one of Excel's built-in complex number functions, this is interpreted as a complex number.

Also the complex number functions can accept a simple numeric value, as this is equivalent to a complex number whose imaginary coefficient is equal to 0.

Therefore, the inumber argument can be supplied to the Excel Imreal function as either:

• A simple number
or
• A complex number encased in quotation marks - eg. "5+3i"
or
• A reference to a cell containing a complex number or a numeric value
or
• A value returned from another Excel function or formula

These are all included in the examples below.

## Excel Imreal Function Examples

In the example below, the Excel Imreal function is used find the real coefficient of different complex numbers.

Formulas:
AB
15+2i=IMREAL( A1 )
2 =IMREAL( "2+2i" )
3 =IMREAL( 6 )
4 =IMREAL( "3i" )
5 =IMREAL( COMPLEX( 4, 1 ) )
Results:
AB
15+2i5
2 2
3 6
4 0
5 4

Further information on the Excel Imreal function can be found on the Microsoft Office website.

## Imreal Function Errors

If you get an error from the Imreal 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 add-in is not enabled in your Excel.You will need to enable the add-in if you want to use the Excel complex number functions.