Standard library header <cmath>

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Standard Library header files

Language Support
<cstddef> <limits> <climits> <contract>	<cfloat> <cstdint> <new> <version>	<typeinfo> <exception> <initializer_list>	<csignal> <csetjmp> <cstdarg>
Concepts
<concepts>
Diagnostics
<stdexcept>	<cassert>	<cerrno>	<system_error>
General utilities
<utility> <memory> <memory_resource> <scoped_allocator> <compare>	<bitset> <tuple> <optional> <any> <variant>	<type_traits> <ratio> <chrono> <typeindex> <functional>	<ctime> <cstdlib>
Strings
<string> <string_view>	<cctype> <cwctype>	<cwchar> <cuchar>	<cstring> <charconv>
Localization
<locale>	<codecvt>	<clocale>
Containers
<span> <array> <vector>	<deque> <forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
Iterators
<iterator>
Algorithms
<algorithm>	<execution>
Numerics
<complex> <random>	<valarray> <numeric>	<cfenv> <cmath>	<bit>
Input/Output
<iosfwd> <ios> <iomanip> <streambuf>	<istream> <ostream> <iostream>	<sstream> <fstream> <syncstream>	<cstdio> <cinttypes> <strstream>
Regular expressions
<regex>
Filesystem support
<filesystem>
Thread support
<thread> <atomic>	<mutex> <shared_mutex>	<condition_variable> <future>
C compatibility
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

This header was originally in the C standard library as <math.h>.

This header is part of the numeric library.

Macro constants

HUGE_VALFHUGE_VALHUGE_VALL (C++11)(C++11)	indicates the overflow value for float, double and long double respectively (macro constant)
INFINITY (C++11)	evaluates to positive infinity or the value guaranteed to overflow a float (macro constant)
NAN (C++11)	evaluates to a quiet NaN of type float (macro constant)
math_errhandlingMATH_ERRNOMATH_ERREXCEPT (C++11)(C++11)(C++11)	defines the error handling mechanism used by the common mathematical functions (macro constant)
Classification
FP_NORMALFP_SUBNORMALFP_ZEROFP_INFINITEFP_NAN (C++11)(C++11)(C++11)(C++11)(C++11)	indicates a floating-point category (macro constant)

Types

float_t (C++11)	most efficient floating-point type at least as wide as float (typedef)
double_t (C++11)	most efficient floating-point type at least as wide as double (typedef)

Functions

Basic operations
abs(float) fabs	absolute value of a floating point value (|x|) (function)
fmod	remainder of the floating point division operation (function)
remainder (C++11)	signed remainder of the division operation (function)
remquo (C++11)	signed remainder as well as the three last bits of the division operation (function)
fma (C++11)	fused multiply-add operation (function)
fmax (C++11)	larger of two floating point values (function)
fmin (C++11)	smaller of two floating point values (function)
fdim (C++11)	positive difference of two floating point values (max(0, x-y)) (function)
nannanfnanl (C++11)(C++11)(C++11)	not-a-number (NaN) (function)
Exponential functions
exp	returns e raised to the given power (ex) (function)
exp2 (C++11)	returns 2 raised to the given power (2x) (function)
expm1 (C++11)	returns e raised to the given power, minus one (ex-1) (function)
log	computes natural (base e) logarithm (ln(x)) (function)
log10	computes common (base 10) logarithm (log10(x)) (function)
log2 (C++11)	base 2 logarithm of the given number (log2(x)) (function)
log1p (C++11)	natural logarithm (to base e) of 1 plus the given number (ln(1+x)) (function)
Power functions
pow	raises a number to the given power (xy) (function)
sqrt	computes square root (x) (function)
cbrt (C++11)	computes cubic root (3x) (function)
hypot (C++11)	computes square root of the sum of the squares of two given numbers (x2 +y2 ) (function)
Trigonometric functions
sin	computes sine (sin(x)) (function)
cos	computes cosine (cos(x)) (function)
tan	computes tangent (tan(x)) (function)
asin	computes arc sine (arcsin(x)) (function)
acos	computes arc cosine (arccos(x)) (function)
atan	computes arc tangent (arctan(x)) (function)
atan2	arc tangent, using signs to determine quadrants (function)
Hyperbolic functions
sinh	computes hyperbolic sine (sh(x)) (function)
cosh	computes hyperbolic cosine (ch(x)) (function)
tanh	hyperbolic tangent (function)
asinh (C++11)	computes the inverse hyperbolic sine (arsinh(x)) (function)
acosh (C++11)	computes the inverse hyperbolic cosine (arcosh(x)) (function)
atanh (C++11)	computes the inverse hyperbolic tangent (artanh(x)) (function)
Error and gamma functions
erf (C++11)	error function (function)
erfc (C++11)	complementary error function (function)
tgamma (C++11)	gamma function (function)
lgamma (C++11)	natural logarithm of the gamma function (function)
Nearest integer floating point operations
ceil	nearest integer not less than the given value (function)
floor	nearest integer not greater than the given value (function)
trunc (C++11)	nearest integer not greater in magnitude than the given value (function)
roundlroundllround (C++11)(C++11)(C++11)	nearest integer, rounding away from zero in halfway cases (function)
nearbyint (C++11)	nearest integer using current rounding mode (function)
rintlrintllrint (C++11)(C++11)(C++11)	nearest integer using current rounding mode with exception if the result differs (function)
Floating point manipulation functions
frexp	decomposes a number into significand and a power of 2 (function)
ldexp	multiplies a number by 2 raised to a power (function)
modf	decomposes a number into integer and fractional parts (function)
scalbnscalbln (C++11)(C++11)	multiplies a number by FLT_RADIX raised to a power (function)
ilogb (C++11)	extracts exponent of the number (function)
logb (C++11)	extracts exponent of the number (function)
nextafternexttoward (C++11)(C++11)	next representable floating point value towards the given value (function)
copysign (C++11)	copies the sign of a floating point value (function)
Classification and comparison
fpclassify (C++11)	categorizes the given floating point value (function)
isfinite (C++11)	checks if the given number has finite value (function)
isinf (C++11)	checks if the given number is infinite (function)
isnan (C++11)	checks if the given number is NaN (function)
isnormal (C++11)	checks if the given number is normal (function)
signbit (C++11)	checks if the given number is negative (function)
isgreater (C++11)	checks if the first floating-point argument is greater than the second (function)
isgreaterequal (C++11)	checks if the first floating-point argument is greater or equal than the second (function)
isless (C++11)	checks if the first floating-point argument is less than the second (function)
islessequal (C++11)	checks if the first floating-point argument is less or equal than the second (function)
islessgreater (C++11)	checks if the first floating-point argument is less or greater than the second (function)
isunordered (C++11)	checks if two floating-point values are unordered (function)
Special mathematical functions
assoc_laguerreassoc_laguerrefassoc_laguerrel (C++17)(C++17)(C++17)	associated Laguerre polynomials (function)
assoc_legendreassoc_legendrefassoc_legendrel (C++17)(C++17)(C++17)	associated Legendre polynomials (function)
betabetafbetal (C++17)(C++17)(C++17)	beta function (function)
comp_ellint_1comp_ellint_1fcomp_ellint_1l (C++17)(C++17)(C++17)	(complete) elliptic integral of the first kind (function)
comp_ellint_2comp_ellint_2fcomp_ellint_2l (C++17)(C++17)(C++17)	(complete) elliptic integral of the second kind (function)
comp_ellint_3comp_ellint_3fcomp_ellint_3l (C++17)(C++17)(C++17)	(complete) elliptic integral of the third kind (function)
cyl_bessel_icyl_bessel_ifcyl_bessel_il (C++17)(C++17)(C++17)	regular modified cylindrical Bessel functions (function)
cyl_bessel_jcyl_bessel_jfcyl_bessel_jl (C++17)(C++17)(C++17)	cylindrical Bessel functions (of the first kind) (function)
cyl_bessel_kcyl_bessel_kfcyl_bessel_kl (C++17)(C++17)(C++17)	irregular modified cylindrical Bessel functions (function)
cyl_neumanncyl_neumannfcyl_neumannl (C++17)(C++17)(C++17)	cylindrical Neumann functions (function)
ellint_1ellint_1fellint_1l (C++17)(C++17)(C++17)	(incomplete) elliptic integral of the first kind (function)
ellint_2ellint_2fellint_2l (C++17)(C++17)(C++17)	(incomplete) elliptic integral of the second kind (function)
ellint_3ellint_3fellint_3l (C++17)(C++17)(C++17)	(incomplete) elliptic integral of the third kind (function)
expintexpintfexpintl (C++17)(C++17)(C++17)	exponential integral (function)
hermitehermitefhermitel (C++17)(C++17)(C++17)	Hermite polynomials (function)
legendrelegendreflegendrel (C++17)(C++17)(C++17)	Legendre polynomials (function)
laguerrelaguerreflaguerrel (C++17)(C++17)(C++17)	Laguerre polynomials (function)
riemann_zetariemann_zetafriemann_zetal (C++17)(C++17)(C++17)	Riemann zeta function (function)
sph_besselsph_besselfsph_bessell (C++17)(C++17)(C++17)	spherical Bessel functions (of the first kind) (function)
sph_legendresph_legendrefsph_legendrel (C++17)(C++17)(C++17)	spherical associated Legendre functions (function)
sph_neumannsph_neumannfsph_neumannl (C++17)(C++17)(C++17)	spherical Neumann functions (function)