Интеграл2

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

typedef double (*func_t) (double);
double half (double eps, double alpha);
double integrand(double t);
double integrate (func_t f, double eps);

double half (double eps, double alpha) {
    double a = 0;
    double b = 1;
    double x;

    while (b - a > eps) {
        x = (a + b) / 2;

        if ((integrate(integrand, a, eps) - alpha)*(integrate(integrand, x, eps) - alpha) > 0) {
            a = x;
        }

        else {
            b = x;
        }
    }

    return x;
}

double integrand(double t) {
    return x*x / ((1 + pow(x, 4)) * sqrt(1 - pow(x, 4)));
}

double integrate (func_t f, double x, double eps) {

    double a = 0;
    double b = 1;
    double value = 0;
    double h = (b - a) / 100;
    double x = a;
    int working = 1;
    double integral_1;
    double integral_2;

    while (working) {
        if (x + h >= b) {
            h = b - x;
            working = 0;
        }

        integral_1 = (x + h - x) * integrand(x);

        integral_2 = (x + h/2 - x) * integrand(x) +  (x + h - x + h / 2) * integrand(x + h / 2);

        if (fabs(integral_1 - integral_2) < eps / 4) {

            value = value + integral_1;
            x = x + h;
            h *= 1.5;
        }
        else if (fabs(integral_1 - integral_2) < eps) {

            value = value + integral_1;
            x = x + h;
        }

        else {
            h = h / 2;
            working = 1;
        }

    return value;
}

int main(void) {
    double eps;
    double x;
    double alpha = M_PI/8;

    printf ("Enter epsilon!\n");

    if (scanf("%lf", &eps) != 1) {
        printf ("Incorrect value!\n");
        return -1;
    }

    x = half(eps, alpha);