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Math Library (libm, -lm)

#include <math.h>

The math library includes the following components:
`<math.h>``<complex.h>``<tgmath.h>``<fenv.h>`

The rest of this manual page describes the functions provided by
`<math.h>`.
Please consult
complex(3),
tgmath(3),
and
fenv(3)
for information on the other components.

Each of the following
double
functions has a
float
counterpart with an
‘`f`’
appended to the name and a
long double
counterpart with an
‘`l`’
appended.
As an example, the
float
and
long double
counterparts of
` double`
`acos(double x)`
are
` float`
`acosf(float x)`
and
` long double`
`acosl(long double x)`,
respectively.
The classification macros and silent order predicates are type generic and
should not be suffixed with
‘`f`’
or
‘`l`’.

Description | |

cbrt | cube root |

fma | fused multiply-add |

hypot | Euclidean distance |

sqrt | square root |

Description | |

fpclassify | classify a floating-point value |

isfinite | determine whether a value is finite |

isinf | determine whether a value is infinite |

isnan | determine whether a value is NaN |

isnormal | determine whether a value is normalized |

Description | |

frexp | extract exponent and mantissa |

ilogb | extract exponent |

ldexp | multiply by power of 2 |

logb | extract exponent |

scalbln | adjust exponent |

scalbn | adjust exponent |

Description | |

copysign | copy sign bit |

fabs | absolute value |

fdim | positive difference |

fmax | maximum function |

fmin | minimum function |

signbit | extract sign bit |

Description | |

nan | generate a quiet NaN |

Description | |

ceil | integer no less than |

floor | integer no greater than |

fmod | positive remainder |

llrint | round to integer in fixed-point format |

llround | round to nearest integer in fixed-point format |

lrint | round to integer in fixed-point format |

lround | round to nearest integer in fixed-point format |

modf | extract integer and fractional parts |

nearbyint | round to integer (silent) |

nextafter | next representable value |

nexttoward | next representable value |

remainder | remainder |

remquo | remainder with partial quotient |

rint | round to integer |

round | round to nearest integer |

trunc | integer no greater in magnitude than |

The
`ceil()`,
`floor()`,
`llround()`,
`lround()`,
`round()`,
and
`trunc()`
functions round in predetermined directions, whereas
`llrint()`,
`lrint()`,
and
`rint()`
round according to the current (dynamic) rounding mode.
For more information on controlling the dynamic rounding mode, see
fenv(3)
and
fesetround(3).

Description | |

isgreater | greater than relation |

isgreaterequal | greater than or equal to relation |

isless | less than relation |

islessequal | less than or equal to relation |

islessgreater | less than or greater than relation |

isunordered | unordered relation |

Description | |

acos | inverse cosine |

acosh | inverse hyperbolic cosine |

asin | inverse sine |

asinh | inverse hyperbolic sine |

atan | inverse tangent |

atanh | inverse hyperbolic tangent |

atan2 | atan(y/x); complex argument |

cos | cosine |

cosh | hyperbolic cosine |

erf | error function |

erfc | complementary error function |

exp | exponential base e |

exp2 | exponential base 2 |

expm1 | exp(x)-1 |

j0 | Bessel function of the first kind of the order 0 |

j1 | Bessel function of the first kind of the order 1 |

jn | Bessel function of the first kind of the order n |

lgamma | log gamma function |

log | natural logarithm |

log10 | logarithm to base 10 |

log1p | log(1+x) |

log2 | base 2 logarithm |

pow | exponential x**y |

sin | trigonometric function |

sinh | hyperbolic function |

tan | trigonometric function |

tanh | hyperbolic function |

tgamma | gamma function |

y0 | Bessel function of the second kind of the order 0 |

y1 | Bessel function of the second kind of the order 1 |

yn | Bessel function of the second kind of the order n |

The routines in this section might not produce a result that is correctly rounded, so reproducible results cannot be guaranteed across platforms. For most of these functions, however, incorrect rounding occurs rarely, and then only in very-close-to-halfway cases.

A math library with many of the present functions appeared in
*AT&T v7 .*
The library was substantially rewritten for
*BSD 4.3*
to provide
better accuracy and speed on machines supporting either VAX
or IEEE 754 floating-point.
Most of this library was replaced with FDLIBM, developed at Sun
Microsystems, in
FreeBSD 1.1.5 .
Additional routines, including ones for
float
and
long double
values, were written for or imported into subsequent versions of FreeBSD.

Many of the routines to compute transcendental functions produce
inaccurate results in other than the default rounding mode.

On the i386 platform, trigonometric argument reduction is not
performed accurately for huge arguments, resulting in
large errors
for such arguments to
`cos()`,
`sin()`,
and
`tan()`.

MATH (3) | December 7, 2017 |

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