exp(3) - f31

1EXP(3)                     Linux Programmer's Manual                    EXP(3)
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NAME

6       exp, expf, expl - base-e exponential function
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SYNOPSIS

9       #include <math.h>
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11       double exp(double x);
12       float expf(float x);
13       long double expl(long double x);
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15       Link with -lm.
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17   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19       expf(), expl():
20           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
21               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
22               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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DESCRIPTION

25       These  functions return the value of e (the base of natural logarithms)
26       raised to the power of x.
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RETURN VALUE

29       On success, these functions return the exponential value of x.
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31       If x is a NaN, a NaN is returned.
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33       If x is positive infinity, positive infinity is returned.
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35       If x is negative infinity, +0 is returned.
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37       If the result underflows, a range error occurs, and zero is returned.
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39       If the result overflows, a range error occurs, and the functions return
40       +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.
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ERRORS

43       See  math_error(7) for information on how to determine whether an error
44       has occurred when calling these functions.
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46       The following errors can occur:
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48       Range error, overflow
49              errno is set to ERANGE.  An  overflow  floating-point  exception
50              (FE_OVERFLOW) is raised.
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52       Range error, underflow
53              errno  is  set to ERANGE.  An underflow floating-point exception
54              (FE_UNDERFLOW) is raised.
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ATTRIBUTES

57       For  an  explanation  of  the  terms  used   in   this   section,   see
58       attributes(7).
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60       ┌──────────────────────┬───────────────┬─────────┐
61       │Interface             │ Attribute     │ Value   │
62       ├──────────────────────┼───────────────┼─────────┤
63       │exp(), expf(), expl() │ Thread safety │ MT-Safe │
64       └──────────────────────┴───────────────┴─────────┘

CONFORMING TO

66       C99, POSIX.1-2001, POSIX.1-2008.
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68       The variant returning double also conforms to SVr4, 4.3BSD, C89.
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COLOPHON

74       This  page  is  part of release 5.02 of the Linux man-pages project.  A
75       description of the project, information about reporting bugs,  and  the
76       latest     version     of     this    page,    can    be    found    at
77       https://www.kernel.org/doc/man-pages/.
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81                                  2017-09-15                            EXP(3)