.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de) .\" .\" %%%LICENSE_START(GPL_NOVERSION_ONELINE) .\" Distributed under GPL .\" %%%LICENSE_END .\" .TH CSQRT 3 2017-09-15 "" "Linux Programmer's Manual" .SH NAME csqrt, csqrtf, csqrtl \- complex square root .SH SYNOPSIS .B #include .PP .BI "double complex csqrt(double complex " z ");" .br .BI "float complex csqrtf(float complex " z ");" .br .BI "long double complex csqrtl(long double complex " z ");" .PP Link with \fI\-lm\fP. .SH DESCRIPTION These functions calculate the complex square root of .IR z , with a branch cut along the negative real axis. (That means that \fIcsqrt(\-1+eps*I)\fP will be close to I while \fIcsqrt(\-1\-eps*I)\fP will be close to \-I, \fIif eps\fP is a small positive real number.) .SH VERSIONS These functions first appeared in glibc in version 2.1. .SH ATTRIBUTES For an explanation of the terms used in this section, see .BR attributes (7). .TS allbox; lbw27 lb lb l l l. Interface Attribute Value T{ .BR csqrt (), .BR csqrtf (), .BR csqrtl () T} Thread safety MT-Safe .TE .sp 1 .SH CONFORMING TO C99, POSIX.1-2001, POSIX.1-2008. .SH SEE ALSO .BR cabs (3), .BR cexp (3), .BR complex (7) .SH COLOPHON This page is part of release 5.10 of the Linux .I man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at \%https://www.kernel.org/doc/man\-pages/.