Standard C Math
| abs | absolute value |
| acos | arc cosine |
| asin | arc sine |
| atan | arc tangent |
| atan2 | arc tangent, using signs to determine quadrants |
| ceil | the smallest integer not less than a certain value |
| cos | cosine |
| cosh | hyperbolic cosine |
| div | returns the quotient and remainder of a division |
| exp | returns “e” raised to a given power |
| fabs | absolute value for floating-point numbers |
| floor | returns the largest integer not greater than a given value |
| fmod | returns the remainder of a division |
| frexp | decomposes a number into scientific notation |
| labs | absolute value for long integers |
| ldexp | computes a number in scientific notation |
| ldiv | returns the quotient and remainder of a division, in long integer form |
| log | natural logarithm (to base e) |
| log10 | common logarithm (to base 10) |
| modf | decomposes a number into integer and fractional parts |
| pow | returns a given number raised to another number |
| sin | sine |
| sinh | hyperbolic sine |
| sqrt | square root |
| tan | tangent |
| tanh | hyperbolic tangent |
Compiling with gcc
In order to use some of the above functions, certain versions of the gcc compiler require the math library to be explicitly linked in using the -lm command-line option.