Author: Oscar Cronquist Article last updated on November 10, 2022

How to use the IMLN function

The IMLN function calculates the natural logarithm of a complex number in x + yi or x + yj text format.

The letter j is used in electrical engineering to distinguish between the imaginary value and the electric current.

The natural logarithm of a complex number is calculated like this:

C = x + yi

IMLN(C) =ln√(x2+y2)+ itan-1(y/x)

1. IMLN Function Syntax

IMLN(inumber)

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2. IMLN Function Arguments

inumber Required. A complex number in x+yi or x+yj text format.

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3. IMLN function example

How to use the IMLN function

The image above demonstrates a formula in cell D3 that calculates the natural logarithm of a complex number specified in cell C3.

Formula in cell D3:

=IMLN(C3)

3.1 Explaining formula

Step 1 - Populate arguments

IMLN(inumber)

becomes

IMLN(C3)

Step 2 - Evaluate the IMLN function

IMLN(C3)

becomes

IMLN("1+2i")

and returns

0.80471895621705+1.10714871779409i

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