# y0(), y0f(), y1(), y1f(), yn(), ynf()bessel functions of the second kind

## SYNOPSIS

#include <math.h>

double y0(double x)

float y0f(float x)

double y1(double x)

float y1f(float x)

double yn(int n, double x)

float ynf(int n, float x)

## DESCRIPTION

The functions y0(), y0f(), y1(), and y1f() compute the linearly independent Bessel function of the second kind of the order 0 and the order 1, respectively, for the positive integer value x (expressed as a double); the functions yn() and ynf() compute the Bessel function of the second kind for the integer order n for the positive integer value x (expressed as a double).

## PARAMETER

x

Is the number whose Bessel function is to be derived.

n

Is the order of the Bessel function.

## RETURN VALUES

If successful, these functions return the Bessel value of x.

If x is NaN or negative, NaN is returned.

If x is 0.0, then:

• In IEEE mode, -HUGE_VAL is returned.

• In POSIX mode, -HUGE_VAL is returned and errno is set to EDOM.

• In SVID mode, -HUGE is returned and matherr() is called.

• In XOPEN mode, -HUGE_VAL is returned and the matherr() function is called.

If x is a negative number, then:

• In IEEE mode, NaN is returned.

• In POSIX mode, -HUGE_VAL is returned and errno is set to EDOM.

• In SVID mode, -HUGE is returned and matherr() is called.

• In XOPEN mode, -HUGE_VAL is returned and the matherr() function is called.

If the result underflows, 0.0 is returned and if in POSIX mode, errno is set to ERANGE. If in XOPEN or SVID mode, the matherr() function is called.

If x is greater than X_TLOSS, then:

• In IEEE mode, the correct answer is returned.

• In POSIX mode, 0.0 is returned, and errno is set to ERANGE.

• In SVID or XOPEN mode, 0.0 is returned the matherr() function is called.

UNIX 98.

MT-Safe.

None.

## AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition