Bisection method III

// para cosx=0, com a=0 e b=3 e epsilon

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

#define pi M_PI
#define eps 1e-5

double bisec(double x)
{
    double f;
    int m=5; //2310

    f=tan(x)-m*x;
    return f;
}

int main(void)
{
    double a=0.1, b=1.57, c, y;
    int i;

    // assert(bisec(a)>0);
    // assert(bisec(b)>0);

    while (fmax(fabs(bisec(a)),fabs(bisec(b)))>eps) // b-a
    {
        c=(a+b)/2;
        y=bisec(c);

        if (y<0)
            a=c;

        else if (y>0)
            b=c;

        else if (y==0)
            break;

        i++;
    }

    printf("Raiz calculada: %e \nIterações = %d \n",c,i);

    return 0;
}