Summary

The Excel IMTAN function returns the tangent of a complex number. 

Purpose 

Get the tangent of a complex number.

Return value 

Returns the tangent of the complex number.

Syntax

=IMTAN(complex_num)
  • complex_num - The complex number in the form "x+yi".

How to use 

The Excel IMTAN function returns the tangent of a complex number. For example, given the complex number "3+4i" as input, the function returns "-0.000187346+0.999355987i"

=IMTAN("3+4i") // returns -0.000187346+0.999355987i

Explanation

In math, the tangent of a complex number is defined in terms of complex sine and cosine functions.

Complex tangent definition.

In Excel, the tangent of a complex number is equivalent to the following formula.

=IMDIV(IMSIN(z),IMCOS(z)) // equivalent to IMTAN(z)

The 3D plot below visualizes the function's real output. The horizontal XY plane represents input from the complex plane, and the vertical axis represents the function's real output.

Real output of the complex tangent function.

The output along the real axis forms the shape of the regular (circular) tangent function.

Real output of the complex tangent function highlight regular tangent.

The imaginary output of the function is visualized by the 3D plot below.

Imaginary output of the complex tangent function.

The output along the imaginary axis forms the shape of the hyperbolic tangent function.

Imaginary output of the complex tangent function highlight hyperbolic tangent.

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Dave Bruns

Hi - I'm Dave Bruns, and I run Exceljet with my wife, Lisa. Our goal is to help you work faster in Excel. We create short videos, and clear examples of formulas, functions, pivot tables, conditional formatting, and charts.