Y1-func
This function returns the first order Bessel function of the second kind and has the following form:
Y1(x)
The formula for the equation is:
where
double y1(double x)
x
Returns the first order Bessel function of second kind at x.
aa = y1(5); aa = ; //0.14786314339123
J0, J1, Jn, Y0, Yn