.\" @(#)j0.3m 6.1 (Berkeley) 5/15/85 .\" .TH J0 3M "May 15, 1985" .AT 3 .SH NAME j0, j1, jn, y0, y1, yn \- bessel functions .SH SYNOPSIS .nf .B #include .PP .B double j0(x) .B double x; .PP .B double j1(x) .B double x; .PP .B double jn(n, x) .B double x; .PP .B double y0(x) .B double x; .PP .B double y1(x) .B double x; .PP .B double yn(n, x) .B double x; .fi .SH DESCRIPTION These functions calculate Bessel functions of the first and second kinds for real arguments and integer orders. .SH DIAGNOSTICS Negative arguments cause .I y0, y1, and .I yn to return a huge negative value and set .I errno to EDOM.