# Manuals/calci/BESSELJ

BESSELJ(x,n)

• is the value to evaluate the function
• is the order of the Bessel function and is an integer.
• BESSELJ(), returns the modified Bessel Function Jn(x).

## Description

• This function gives the value of the modified Bessel function.
• Bessel functions is also called Cylinder Functions because they appear in the solution to Laplace's equation in cylindrical coordinates.
• Bessel's Differential Equation is defined as:

where is the arbitrary Complex Number.

• But in most of the cases is the non-negative real number.
• The solutions of this equation are called Bessel Functions of order n.
• Bessel functions of the first kind, denoted as
• The Bessel function of the first kind of order can be expressed as:

• where or
• is the Gamma Function.
• This function will give result as error when
1.  or  is non numeric
2. , because  is the order of the function.


## ZOS

• The syntax is to calculate BESSELJ in ZOS is .
• is the value to evaluate the function
• is the order of the Bessel function and is an integer.
• For e.g.,BESSELJ(0.789..0.901..0.025,5)

## Examples

1. BESSELJ(2,3) = 0.12894324997562717
2. BESSELJ(7,2) = -0.3014172238218034
3. BESSELJ(5,1) = -0.3275791385663632

BESSEL Equation