# BESSELI Function

The BESSELI function is one of the engineering functions. It is used to return the modified Bessel function, which is equivalent to the Bessel function evaluated for purely imaginary arguments.

The BESSELI function syntax is:

BESSELI(X, N)

where

X is the value at which to evaluate the function,

N is the order of the Bessel function, a numeric value greater than or equal to 0.

The numeric values can be entered manually or included into the cell you make reference to.

To apply the BESSELI function,

1. select the cell where you wish to display the result,
2. click the Insert function icon situated at the top toolbar,
   or right-click within a selected cell and select the Insert Function option from the menu,
   or click the icon situated at the formula bar,
3. select the Engineering function group from the list,
4. click the BESSELI function,
5. enter the required arguments separating them by comma,
6. press the Enter button.

The result will be displayed in the selected cell.