UVa 10341 - Solve It

// UVa 10341 - Solve It
#include <iostream>
#include <stdio.h>
#include <math.h>
using namespace std;

double p, q, r, s, t, u;
double epsilon = 0.0000001;

double f(double x) {
	return p * exp(-x) + q * sin(x) + r * cos(x) + s * tan(x) + t * x * x + u;
}

double bisection(double left, double right) {
	while (left + epsilon < right) {
		double mid = (left + right) / 2;
		if (f(left) * f(mid) <= 0)
			right = mid;
		else
			left = mid;
	}
	return left;
}

int main() {

	while (cin >> p >> q >> r >> s >> t >> u) {
		if (f(0) * f(1) > 0)
			cout << "No solution" << endl;
		else
			printf("%.4f\n", bisection(0, 1));
	}

	return 0;
}