Jacobian Elliptic Functions (Not in Base Package)

Determines the Jacobian elliptic functions cn, dn, and sn. Details  

	x is the input argument.
	k is the integrand parameter.
	cn returns the value of the Jacobi elliptic function cn.
	dn returns the Jacobi elliptic function dn.
	sn returns the value of the Jacobi elliptic function sn.
	phi is the upper limit of the integral defining the function.

Jacobian Elliptic Functions Details

The following equations define the three Jacobian elliptic functions.

cn(x, k) = cos()

sn(x, k) = sin()

where

The function is defined according to the following intervals for the input values.

For any real value of integrand parameter k in the unit interval, the function is defined for all real values of x.