/* ---------------------------------- */
/* save as c17b.c                    */
/* --------------------------------- */
#include "x_hfile.h"
#include      "fb.h"
/* --------------------------------- */
int main(void)
{
double ay = -2;
double by =  2;
int    ny =  2*20;

int    nx =  2*20;

double m  = 0;
double Mx = 0;
double My = 0;

 clrscrn();

 printf(" Find the mass and the center of mass of the lamina\n");
 printf(" that has the shape of the region bounded by the   \n");
 printf(" graphs of the given equations.\n\n");

 printf(" x = y**2, x = 4,  \n\n");
 printf(" and if f(x,y), the area mass density at the point P(x,y),      \n");
 printf(" is directly proportional to the distance from the y-axis to P\n\n");
 printf(" f : (x,y)-> %s    \n\n", feq);
 printf(" These give :      \n\n");
 printf(" by :         %+.1f   \n",  by);
 printf(" ay :         %+.1f \n\n",  ay);
 printf("  u :   (y)-> %s      \n", ueq);
 printf("  v :   (y)-> %s    \n\n", veq);
 stop();

 clrscrn();

   m = simpson_dxdy(f,u,v,nx,ay,by,ny);
 printf(" Compute the mass m.\n");
 printf("         (by     (v(y)\n");
 printf(" m =  int(   int(     f(x,y)  dx dy = %.1f\n", m);
 printf("         (ay     (u(y)\n\n");

   Mx = simpson_dxdy(h,u,v,nx,ay,by,ny);
 printf(" Compute the moment Mx.\n");
 printf("         (by     (v(y)\n");
 printf(" Mx = int(   int(    y  f(x,y)  dx dy = %.1f\n", Mx);
 printf("         (ay     (u(y)\n\n");

   My = simpson_dxdy(g,u,v,nx,ay,by,ny);
 printf(" Compute the moment My.\n");
 printf("         (by     (v(y)\n");
 printf(" My = int(   int(     x  f(x,y)  dx dy = %.1f\n", My);
 printf("         (ay     (u(y)\n\n");

 printf("   The center of mass is (X,Y)\n\n");
 printf("     X = My/m = %.2f     Y = Mx/m = %.2f\n\n",My/m,Mx/m);
 stop();
 
 return 0;
}
/* --------------------------------- */
/* --------------------------------- */