# Power Pivot Principles: The A to Z of DAX Functions – COSH

9 August 2022

*In
our long-established Power Pivot Principles articles, we continue our series on
the A to Z of Data Analysis eXpression (DAX) functions. This week, we look at COSH.*

* *

*The
COSH function*

You probably think we talk a load of hyperbolics
here, but that’s what happens when we are under the **COSH**. This function returns
the hyperbolic cosine of a number.

That’s all well and good if you know what “hyperbolic cosine” means. In mathematics, hyperbolic functions are analogous to the trigonometric, or circular, functions, such as sine and cosine.

Just as the points **(cos t, sin t)** form a circle with a unit radius, the
points **(cosh z, sinh z)** form the right half of the equilateral hyperbola (please see the figure below).
The hyperbolic functions take a real
argument called a hyperbolic angle. The
size of a hyperbolic angle is twice the area of its hyperbolic sector. The hyperbolic functions may be defined in
terms of the legs of a right triangle covering this sector.

Hyperbolic functions occur in the solutions of many linear differential equations, such as some cubic equations. Further, in complex analysis, the hyperbolic functions arise as the imaginary parts of sine and cosine – but that’s a story for another day.

The **COSH **function
employs the following syntax to operate:

**COSH(number)**

The **COSH** function has the following arguments:

**number:**this is required and represents any real number for which you want to find the hyperbolic cosine.

It should be further noted that the formula for the hyperbolic cosine is:

This function is not supported for use in DirectQuery mode when used in calculated columns or row-level security (RLS) rules

Please see my example below:

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