# A to Z of Excel Functions: The COT Function

17 November 2017

**The COT function**

This function returns the *cotangent* of the given angle. For those of you who don’t find trigonometry riveting you really shouldn’t be so obtuse, but the cotangent is the inverse of the tangent function, *i.e. *it calculates the ratio of the adjacent side of a triangle divided by the opposite side (subject to sign considerations), *viz.*

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

**COT(number)**

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

**number:**this is required and represents the angle in radians for which you want the cotangent.

It should be further noted that if the angle is in degrees, you should multiply the angle by **PI()/180** or else use the **RADIANS** function to convert the angle to radians. Furthermore:

- The absolute value of
**number**must be less than 2^27 - If
**number**is outside its constraints,**COT**returns the*#NUM!*error value - If
**number**is a non-numeric value,**COT**returns the*#VALUE!*error value **COT(0)**returns the*#DIV/0!*error value.

Please see my example below:

*We’ll continue our A to Z of Excel Functions soon. Keep checking back – there’s a new blog post every other business day.*

*A full page of the function articles can be found here. *