C programming language provides a set of built-in math functions that can be used to perform various mathematical operations. In many situations the mathematical functions such as sqrt(), pow(), round(), log() etc. are needed. Almost every C compiler supports these basic mathematical functions. All these functions are defined in <math.h> header file. The math.h header defines various mathematical functions including trigonometric and hyperbolic functions So, we must include this file in the beginning of the program as  #include<math.h> . The commonly used functions of math.h header file are given below:
| Function | Description |
1. | ceil(number) | Rounds up the given number. It returns the integer value which is greater than or equal to given number. |
2 | floor(number) |
Rounds down the given number. It returns the integer value which is less than or equal to given number. |
3 | sqrt(number) |
returns the square root of given number. |
4 | pow(base, exponent) |
returns the power of given number. |
5 | fabs(number) |
returns the absolute value of a number. |
6 | round() |
returns the nearest integer value of the given number |
7 | log() |
computes the natural logarithm of an argument. |
8 | log10() |
returns the logarithm to the base of 10. |
9 | exp() |
returns the result of e raised to the power of x. |
10 | frexp() |
splits a floating-point value into a fraction and an exponent. |
11 | fmod() |
returns the remainder |
12 | sin() |
returns the sine of a number. |
13 | sinh() |
returns the hyperbolic sine of a number |
14 | cos() |
Returns the cosine of a number |
15 |
cosh() |
Returns the hyperbolic cosine of a number |
16 |
tan() |
returns tangent of the argument passed. |
17 |
tanh() |
computes the hyperbolic tangent of an argument. |
18 |
asin() |
Returns the arc sine of a number |
19 |
acos() |
Returns the arc cosine of a number |
20 |
atan(d) |
Returns the arc tangent of a number |
Example of Math Functions found in math.h header file:
Output: