While basic arithmetics works well for many tasks, sometimes more complex math is needed. C provides a set of math functions for performing some common math operations which include trigonometric functions, exponential and logarithmic functions, power and absolute-value functions, and nearest integer functions.

The function prototype and macro definitions for the math functionality discussed in this article can be can accessed by including the <math.h> standard header.

On some compilers, due to historical reasons, the math library is stored separated from the rest of the standard C library. In those compilers, you must specify an additional compiler option -lm to link against the math library.