A Little C Primer/C Math Library

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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.