Math.h

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Math.h

math.h is a header file in the standard library

C standard library

The C standard library consists of a set of sections of the ISO C standard which describe a collection of header files and library routines used to implement common operations, such as input/output and character string handling, in the C ....
of C programming language designed for basic mathematical operations. Most of the functions involve the use of floating point

Floating point

In computing, floating point describes a system for numerical representation in which a String of digits represents a rational number.The term floating point refers to the fact that the radix point can "float": that is, it can be placed anywhere relative to the Significant figures of the number....
numbers. C++

C++

C++ is a general-purpose programming language. It is regarded as a middle-level language, as it comprises a combination of both high-level programming language and low-level programming language language features....
also implements these functions for compatibility reasons and declares them in the header cmath.

All functions that take or return an angle work in radians.

All these functions take doubles for floating-point arguments, unless otherwise specified.

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Encyclopedia

math.h is a header file in the standard library

C standard library

Floating point

C++

Pre-C99 functions

Name	Description
`acos`	inverse cosine
`asin`	inverse sine
`atan`	one-parameter inverse tangent
`atan2`	two-parameter inverse tangent Atan2 In trigonometry, the two-argument function atan2 is a variation of the arctangent function. For any real number arguments x and y not both equal to zero, atan2 is the angle in radians between the positive x-axis of a plane and the point given by the Cartesian coordinate system on it....
`ceil`	ceiling, the smallest integer Integer The integers are natural numbers including 0 and their negative and non-negative numberss . They are numbers that can be written without a fractional or decimal component, and fall within the set .... not less than parameter
`cos`	cosine
`cosh`	hyperbolic cosine
`exp`	exponential Exponential Exponential may refer to any of several mathematical topics related to exponentiation, including:Exponential function, also:*Matrix exponential, the matrix analogue to the above... function
`fabs`	absolute value Absolute value In mathematics, the absolute value of a real number is its numerical value without regard to its Negative and non-negative numbers. So, for example, 3 is the absolute value of both 3 and -3.... (of a floating-point number)
`floor`	floor, the largest integer not greater than parameter
`fmod`	floating-point remainder FMOD FMOD is a commercial audio Library made by Firelight Technologies that plays music files of diverse Audio file format on many different Platform ....
`frexp`	break floating-point number down into mantissa Significand The significand is the part of a floating point that contains its significant digits. Depending on the interpretation of the exponent, the significand may be considered to be an integer or a fraction .... and exponent
`ldexp`	scale floating-point number by exponent (see article Ldexp In computing, ldexp is a function that multiplies a double precision floating point value by a specified integral power of two, returning the result if it is a valid floating point value for the representation used for double precision floating point values in the execution environment.... )
`log`	natural logarithm Natural logarithm The natural logarithm, formerly known as the hyperbolic logarithm, is the logarithm to the base e , where e is an irrational number constant approximately equal to 2.718281828....
`log10`	base-10 logarithm Common logarithm The common logarithm is the logarithm with base 10. It is also known as the decadic logarithm, named after its base. It is indicated by log10, or sometimes Log with a capital L ....
`modf(x,p)`	returns fractional part of x and stores integral part where pointer p points to
`pow(x,y)`	raise x to the power of y, x^y
`sin`	sine Siné Maurice Sinet, known as Sin? is a France cartoonist.As a young man he studied drawing and graphic arts, earning his life as a cabaret singer....
`sinh`	hyperbolic sine
`sqrt`	square root Square root In mathematics, a square root of a number x is a number r such that r2 = x, or, in other words, a number r whose square is x....
`tan`	tangent
`tanh`	hyperbolic tangent

C99 functions

Name	Description
`acosh`	inverse hyperbolic cosine Inverse hyperbolic function The inverse functions of the hyperbolic functions are the area hyperbolic functions. The names hint at the fact that they compute the area of a hyperbolic sector in the same way that the inverse trigonometric functions compute the arclength of a sector on the unit circle ...
`asinh`	inverse hyperbolic sine Inverse hyperbolic function The inverse functions of the hyperbolic functions are the area hyperbolic functions. The names hint at the fact that they compute the area of a hyperbolic sector in the same way that the inverse trigonometric functions compute the arclength of a sector on the unit circle ...
`atanh`	inverse hyperbolic tangent Inverse hyperbolic function The inverse functions of the hyperbolic functions are the area hyperbolic functions. The names hint at the fact that they compute the area of a hyperbolic sector in the same way that the inverse trigonometric functions compute the arclength of a sector on the unit circle ...
`cbrt`	cube root Cube root In mathematics, a cube root of a number, denoted or x1/3, is a number a such that a3 = x. All real numbers have exactly one real number cube root and a pair of complex conjugate roots, and all nonzero complex numbers have three distinct complex cube roots....
`copysign(x,y)`	returns the value of x with the sign of y
`erf`	error function Error function In mathematics, the error function is a special function which occurs in probability, statistics, materials science, and partial differential equations....
`erfc`	complementary error function
`exp2(x)`	raise 2 to the power of x, 2^x
`expm1(x)`	one less than the exponential of x, e^x − 1
`fdim(x,y)`	positive difference between x and y, fmax(x−y, 0)
`fma(x,y,z)`	multiply and add, (x * y) + z
`fmax(x,y)`	largest value of x and y
`fmin(x,y)`	smallest value of x and y
`hypot(x,y)`	hypotenuse Hypotenuse File:Triangle Sides.svgA hypotenuse is the longest side of a right triangle, the side opposite the right angle. The length of the hypotenuse of a right triangle can be found using the Pythagorean theorem, which states that the Square of the length of the hypotenuse equals the sum of the squares of the lengths of the other two sides.... , sqrt(x² + y²)
`ilogb`	the exponent of a floating-point value, converted to an `int`
`lgamma`	natural log of the absolute value Absolute value In mathematics, the absolute value of a real number is its numerical value without regard to its Negative and non-negative numbers. So, for example, 3 is the absolute value of both 3 and -3.... of the gamma function Gamma function In mathematics, the Gamma function is an extension of the factorial function to real number and complex number numbers. For a complex number z with positive real part the Gamma function is defined by...
`llrint`	round to integer (returns `long long`) using current rounding mode
`lrint`	round to integer (returns `long`) using current rounding mode
`llround`	round to integer (returns `long long`)
`lround`	round to integer (returns `long`)
`log1p(x)`	natural logarithm Natural logarithm The natural logarithm, formerly known as the hyperbolic logarithm, is the logarithm to the base e , where e is an irrational number constant approximately equal to 2.718281828.... of 1 + x
`log2`	base-2 logarithm Binary logarithm In mathematics, the binary logarithm is the logarithm for base 2. It is the inverse function of ....
`logb`	extract exponent from floating-point number
`nan(s)`	returns NaN NaN In computing, NaN, which stands for Not a Number, is a value or symbol that is usually produced as the result of an operation on invalid input operands, especially in floating point calculations.... , possibly using string argument
`nearbyint`	round floating-point number to nearest integer
`nextafter(x,y)`	returns next representable value after x (towards y)
`nexttoward(x,y)`	same as `nextafter`, except y is always a `long double`
`remainder(x,y)`	calculates remainder, as required by IEC 60559
`remquo(x,y,p)`	same as `remainder`, but store quotient (as `int`) at target of pointer p
`rint`	round to integer (returns `int`) using current rounding mode
`round`	round to integer (returns `int`)
`scalbln(x,n)`	x * `FLT_RADIX`ⁿ (n is `long`)
`scalbn(x,n)`	x * `FLT_RADIX`ⁿ (n is `int`)
`tgamma`	gamma function Gamma function In mathematics, the Gamma function is an extension of the factorial function to real number and complex number numbers. For a complex number z with positive real part the Gamma function is defined by...
`trunc`	truncate floating-point number

XSI Extensions

Extra functions may be available as X/Open

X/Open

X/Open Company, Ltd. was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of information technology....
System Interfaces Extensions. These are not present in any ANSI or ISO C standard.

Name	Description
`j0(x)`	Bessel function Bessel function In mathematics, Bessel functions, first defined by the mathematician Daniel Bernoulli and generalized by Friedrich Bessel, are Canonical#Mathematics solutions y of Bessel's differential equation:... of x of the first kind of order 0
`j1(x)`	Bessel function of x of the first kind of order 1
`jn(n,x)`	Bessel function of x of the first kind of order n
`scalb(x,y)`	x * `FLT_RADIX`^y (x and y are `double`s)
`y0(x)`	Bessel function of x of the second kind of order 0
`y1(x)`	Bessel function of x of the second kind of order 1
`yn(n,x)`	Bessel function of x of the second kind of order n

The double-to-string conversion functions ecvt, fcvt and gcvt have been deprecated in favour of sprintf.

Extra links

, a reference of all math.h functions