BESSELI

Returns the modified Bessel function, which is equivalent to the Bessel function evaluated for purely imaginary arguments.

If this function is not available, run the Setup program to install the Analysis ToolPak. After you install the Analysis ToolPak, you must enable it by using the Add-Ins command on the Tools menu.

Syntax

BESSELI(x,n)

X   is the value at which to evaluate the function.

N   is the order of the Bessel function. If n is not an integer, it is truncated.

Remarks

• If x is nonnumeric, BESSELI returns the #VALUE! error value.
• If n is nonnumeric, BESSELI returns the #VALUE! error value.
• If n < 0, BESSELI returns the #NUM! error value.
• The n-th order modified Bessel function of the variable x is:

  

Example

BESSELI(1.5, 1) equals 0.981666