# A Little C Primer/C Math Library

This chapter discusses some useful standard C libraries:

- math library
- standard utility library
- the "sprintf()" function
- string function library
- character class test library

And the following minor topics:

- command-line arguments
- dynamic memory allocation
- pointers to functions
- PC memory model and other declarations
- troubleshooting hints

The math library requires the declaration:

#include <math.h>

The math functions consist of:

sin( x ) Sine of x. cos( x ) Cosine of x. tan( x ) Tangent of x. asin( x ) Inverse sine of x. acos( x ) Inverse cosine of x. atan( x ) Inverse tangent of x. sinh( x ) Hyperbolic sine of x. cosh( x ) Hyperbolic cosine of x. tanh( x ) Hyperbolic tangent of x. exp( x ) Exponential function -- e^x. log( x ) Natural log of x. log10( x ) Base 10 log of x. pow( x, y ) Power function -- x^y. sqrt( x ) Square root of x. ceil( x ) Smallest integer not less than x, returned as double. floor( x ) Greatest integer not greater than x, returned as double. fabs( x ) Absolute value of x.

All values are "doubles", and trig values are expressed in radians.