# besselk

besselk(nu, x)

Modified Bessel function of the second kind of order nu, $K_\nu(x)$.

## Examples

The besselk function in Julia calculates the modified Bessel function of the second kind, denoted as K_ν(x), where ν is the order and x is the argument.

Here are some examples of how to use the besselk function:

1. Calculate K_0(x) for a specific value:

julia> besselk(0, 2.5)
0.1842676902057126

This example calculates the value of the modified Bessel function of the second kind with order 0 (K_0(x)) at x = 2.5.

2. Evaluate K_2.5(x) for an array of values:

julia> x = [1.0, 2.0, 3.0, 4.0];
julia> besselk(2.5, x)
4-element Array{Float64,1}:
0.5866369321861473
0.2346365252067939
0.08793892698659256
0.03146419392390222

In this example, we calculate the modified Bessel function of the second kind with order 2.5 (K_2.5(x)) for each value in the array x.

3. Use a variable for the order ν:
julia> ν = 1.5;
julia> besselk(ν, 3.0)
0.11389387274953318

Here, a variable ν is used to represent the order, and the function calculates K_ν(x) at x = 3.0.

Remember that the besselk function only accepts scalar or array-like inputs for both ν and x.