3.3. Mathematical FunctionsΒΆ

The math library has several functions to do mathematical calculations. Except for pow(), each of these programs takes a single double variable. The following sample of math functions all return a double.

sqrt(x) \sqrt{x}

pow(x,y) x^y

exp(x) e^x

fabs(x) |x|

log(x) \ln(x)

log10(x) \log(x)

sin(x), cos(x), tan(x) Trig functions, x is in radians.

The following file lists more math functions and definitions. math_h.txt

Additional documentation may be found by searching the Internet or a variety of other sources of documentation.

Note

To use the math functions On Unix platforms, in addition to including the math.h header file in the program it is necessary and to link in the math library with the -lm option to the compiler.

#include <stdio.h>
#include <math.h>

int main(void)
{
   printf("%6.3lf\t %6.3lf\t %6.3lf\n",
               exp(1.0), log(2.72), log10(100.0));
   return 0;
}

285 hudson:~> gcc -lm test.c
286 hudson:~> ./a.out
 2.718     1.001    2.000