# 3.5.1.3.11 Bessel_j0

## Definition:

$j0= bessel\_j0(x)$, evaluates the Bessel function of the first kind,$J_0(x)$ . The approximation is based on Chebyshev expansions.

For more information please review the s17aec function in the NAG document.

## Parameters:

x (input, double)
The argument x of the function.
j0 (output, double)
The approximation of the Bessel function.