tanl(3) [suse man page]
TAN(3) Linux Programmer's Manual TAN(3) NAME
tan, tanf, tanl - tangent function SYNOPSIS
#include <math.h> double tan(double x); float tanf(float x); long double tanl(long double x); Link with -lm. Feature Test Macro Requirements for glibc (see feature_test_macros(7)): tanf(), tanl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99 DESCRIPTION
The tan() function returns the tangent of x, where x is given in radians. RETURN VALUE
On success, these functions return the tangent of x. If x is a NaN, a NaN is returned. If x is positive infinity or negative infinity, a domain error occurs, and a NaN is returned. If the correct result would overflow, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with the mathematically correct sign. ERRORS
See math_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur: Domain error: x is an infinity An invalid floating-point exception (FE_INVALID) is raised. Range error: result overflow An overflow floating-point exception (FE_OVERFLOW) is raised. These functions do not set errno. CONFORMING TO
C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89. SEE ALSO
acos(3), asin(3), atan(3), atan2(3), cos(3), ctan(3), sin(3) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2008-08-05 TAN(3)
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ATAN2(3) Linux Programmer's Manual ATAN2(3) NAME
atan2, atan2f, atan2l - arc tangent function of two variables SYNOPSIS
#include <math.h> double atan2(double y, double x); float atan2f(float y, float x); long double atan2l(long double y, long double x); Link with -lm. Feature Test Macro Requirements for glibc (see feature_test_macros(7)): atan2f(), atan2l(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99 DESCRIPTION
The atan2() function calculates the principal value of the arc tangent of y/x, using the signs of the two arguments to determine the quad- rant of the result. RETURN VALUE
On success, these functions return the principal value of the arc tangent of y/x in radians; the return value is in the range [-pi, pi]. If y is +0 (-0) and x is less than 0, +pi (-pi) is returned. If y is +0 (-0) and x is greater than 0, +0 (-0) is returned. If y is less than 0 and x is +0 or -0, -pi/2 is returned. If y is greater than 0 and x is +0 or -0, pi/2 is returned. If either x or y is NaN, a NaN is returned. If y is +0 (-0) and x is -0, +pi (-pi) is returned. If y is +0 (-0) and x is +0, +0 (-0) is returned. If y is a finite value greater (less) than 0, and x is negative infinity, +pi (-pi) is returned. If y is a finite value greater (less) than 0, and x is positive infinity, +0 (-0) is returned. If y is positive infinity (negative infinity), and x is finite, pi/2 (-pi/2) is returned. If y is positive infinity (negative infinity) and x is negative infinity, +3*pi/4 (-3*pi/4) is returned. If y is positive infinity (negative infinity) and x is positive infinity, +pi/4 (-pi/4) is returned. ERRORS
No errors occur. CONFORMING TO
C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89. SEE ALSO
acos(3), asin(3), atan(3), carg(3), cos(3), sin(3), tan(3) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2008-11-20 ATAN2(3)