sqrt.3

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

.th SQRT III 3/15/72
.sh NAME
sqrt \*- square root function
.sh SYNOPSIS
.br
.ft B
jsr	pc,sqrt
.s3
double sqrt(x)
.br
double x;
.ft R
.sh DESCRIPTION
The
square root of fr0 (resp. \fBx\fR) is returned (in fr0).
.sh DIAGNOSTICS
The c-bit is
set on negative arguments and 0 is returned.
There is no error return for C programs.
.sh BUGS
No error return from C.