Header File 

math.h  

Category 

Math Routines 

Prototype 

double poly(double x, int degree, double coeffs[]); 

long double polyl(long double x, int degree, long double coeffs[]); 

Description 

Generates a polynomial from arguments. 

poly generates a polynomial in x, of degree degree, with coefficients coeffs[0], coeffs[1], ..., coeffs[degree]. For example, if n = 4, the generated polynomial is: 

polyl is the long double version; it takes long double arguments and returns a long double result. 

Return Value 

poly and polyl return the value of the polynomial as evaluated for the given x. 

Example  

#include <stdio.h>
#include <math.h>
/* polynomial:  x**3 - 2x**2 + 5x - 1 */
int main(void)
{
  double array[] = { -1.0, 5.0, -2.0, 1.0
};
  double result;
  result = poly(2.0, 3, array);
  printf("The polynomial: x**3 - 2.0x**2 + 5x - 1 at 2.0 is %lf\n", result);
  return 0;
}

Portability