Bispol ?

//Bispol
#include <stdio.h>
#include <conio.h>
#include <math.h>
#define pi 3.141592

typedef unsigned char LOGIC;
LOGIC bis(float,float,float,float *);
float f(float);
void caut(float*, float*);

int main(void)
{
  float rad;
  float ls=-15, ld=15;
  float er=1e-3 ;

  caut(&ls,&ld);
  printf("\n main(): ls: %f, ld: %f", ls, ld);

  if(bis(ls,ld,er,&rad)) printf("\nRadacina este = %f",rad);
  else printf("\nEroare");

  getch();
  return 1;
}

LOGIC bis(  float ls,
            float ld,
            float er,
            float *pRad)
{
   float xm;

   if(f(ls)*f(ld)>0) {return(0);}
   if(f(ls)==0) {*pRad=ls; return(1);}
   if(f(ld)==0) {*pRad=ld; return(1);}

   xm=(ls+ld)/2;
   while(fabs(ls-ld)>er && f(xm)!=0)
   {
      xm=(ls+ld)/2;
      if(f(xm)*f(ls)<0) ld=xm;
      else ls=xm;
      }
   *pRad=xm;
   return(1);
}

float Valpol(int n,float A[],float pct)
{
  int i;
  float b;

  b=A[n];
  for(i=n-1;i>=0;i--) b=A[i]+pct*b;
  return b;
}

void caut(  float *pA,
            float *pB)
{
    int numar=0;
    float p_ant = *pA, p_urm, pas = 1e-2 ;

    do{
        p_urm = p_ant + pas ;
        if(f(p_ant) * f(p_urm) < 0) break ;
        p_ant = p_urm;
        printf("\n ls: %f, f(%ls): %f; ld: %f, f(%f): %f",
                                p_ant, p_ant, f(p_ant), p_urm, p_urm, f(p_urm)) ;
        numar++ ;
        if((numar % 10 ==0) && numar != 0) getch();
        } while(p_urm <= *pB) ;
    *pA = p_ant;
    *pB = p_urm;
}

float f(float x) {
    float Ve = 5, ve = 6*sin(2*pi*x), r1 = 1e2, r2=1e3;

    return r2/(r1+r2)*(Ve+ve);
}