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COS(3P) POSIX Programmer's Manual COS(3P)PROLOGThis manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may dif- fer (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.NAMEcos, cosf, cosl - cosine functionSYNOPSIS#include<math.h>doublecos(doublex);floatcosf(floatx);longdoublecosl(longdoublex);DESCRIPTIONThese functions shall compute the cosine of their argumentx, measured in radians. An application wishing to check for error situations should seterrnoto zero and callfeclearex-cept(FE_ALL_EXCEPT) before calling these functions. On return, iferrnois non-zero orfetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.RETURNVALUEUpon successful completion, these functions shall return the cosine ofx. Ifxis NaN, a NaN shall be returned. Ifxis ?0, the value 1.0 shall be returned. Ifxis ?Inf, a domain error shall occur, and either a NaN (if supported), or an implementation-defined value shall be returned.ERRORSThese functions shall fail if: Domain Error Thexargument is ?Inf. If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, thenerrnoshall be set to [EDOM]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point excep- tion shall be raised.Thefollowingsectionsareinformative.EXAMPLESTakingtheCosineofa45-DegreeAngle#include<math.h>...doubleradians=45*M_PI/180;doubleresult;...result=cos(radians);APPLICATIONUSAGEThese functions may lose accuracy when their argument is near an odd multiple of pi/2 or is far from 0. On error, the expressions (math_errhandling & MATH_ERRNO) and (math_errhandling & MATH_ERREXCEPT) are indepen- dent of each other, but at least one of them must be non-zero.RATIONALENone.FUTUREDIRECTIONSNone.SEEALSOacos(),feclearexcept(),fetestexcept(),isnan(),sin(),tan(), the Base Definitions volume of IEEE Std 1003.1-2001, Section 4.18, Treatment of Error Conditions for Mathematical Functions,<math.h>COPYRIGHTPortions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Stan- dard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifica- tions Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Stan- dard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html . IEEE/The Open Group 2003 COS(3P)