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diff --git a/man3/tan.3 b/man3/tan.3 new file mode 100644 index 0000000..b0b185e --- /dev/null +++ b/man3/tan.3 @@ -0,0 +1,147 @@ +'\" t +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk +.\" <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) +.\" Modified 2002-07-27 by Walter Harms +.\" (walter.harms@informatik.uni-oldenburg.de) +.\" +.TH tan 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +tan, tanf, tanl \- tangent function +.SH LIBRARY +Math library +.RI ( libm ", " \-lm ) +.SH SYNOPSIS +.nf +.B #include <math.h> +.PP +.BI "double tan(double " x ); +.BI "float tanf(float " x ); +.BI "long double tanl(long double " x ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.BR tanf (), +.BR tanl (): +.nf + _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L + || /* Since glibc 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE +.fi +.SH DESCRIPTION +These functions return the tangent of +.IR x , +where +.I x +is +given in radians. +.SH RETURN VALUE +On success, these functions return the tangent of +.IR x . +.PP +If +.I x +is a NaN, a NaN is returned. +.PP +If +.I x +is positive infinity or negative infinity, +a domain error occurs, +and a NaN is returned. +.PP +If the correct result would overflow, +a range error occurs, +and the functions return +.BR HUGE_VAL , +.BR HUGE_VALF , +or +.BR HUGE_VALL , +respectively, with the mathematically correct sign. +.\" I think overflow can't occur, because the closest floating-point +.\" representation of pi/2 is still not close enough to pi/2 to +.\" produce a large enough value to overflow. +.\" Testing certainly seems to bear this out. -- mtk, Jul 08 +.\" +.\" POSIX.1 allows an optional underflow error; +.\" glibc 2.8 doesn't do this +.\" POSIX.1 an optional range error for subnormal x; +.\" glibc 2.8 doesn't do this +.SH ERRORS +See +.BR math_error (7) +for information on how to determine whether an error has occurred +when calling these functions. +.PP +The following errors can occur: +.TP +Domain error: \fIx\fP is an infinity +.I errno +is set to +.B EDOM +(but see BUGS). +An invalid floating-point exception +.RB ( FE_INVALID ) +is raised. +.TP +Range error: result overflow +.\" Unable to test this case, since the best approximation of +.\" pi/2 in double precision only yields a tan() value of 1.633e16. +.\" .I errno +.\" is set to +.\" .BR ERANGE . +An overflow floating-point exception +.RB ( FE_OVERFLOW ) +is raised. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR tan (), +.BR tanf (), +.BR tanl () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH STANDARDS +C11, POSIX.1-2008. +.SH HISTORY +C99, POSIX.1-2001. +.PP +The variant returning +.I double +also conforms to +SVr4, 4.3BSD, C89. +.SH BUGS +Before glibc 2.10, the glibc implementation did not set +.\" http://sourceware.org/bugzilla/show_bug.cgi?id=6782 +.I errno +to +.B EDOM +when a domain error occurred. +.SH SEE ALSO +.BR acos (3), +.BR asin (3), +.BR atan (3), +.BR atan2 (3), +.BR cos (3), +.BR ctan (3), +.BR sin (3) |