#include #include #include using namespace std; //F(x) = 6 * x^7+8*x^6+7*x^3+5*x^2-y*x double f1(double x, double y) { return 6 * pow(x, 7) + 8 * pow(x, 6) + 7 * pow(x, 3) + 5 * pow(x, 2) - y * x; } double f2(double x, double y) { return 42 * pow(x, 6) + 48 * pow(x, 5) + 21 * pow(x, 2) + 10 * x - y; } int main() { int T; double y, ans, tmp, ans1; scanf("%d", &T); while (T--) { ans = 1e100; scanf("%lf", &y); double l = 0, r = 100, m; while (abs(r - l) > 1e-6) { m = (l + r) / 2; if (f2(m, y) > 0) r = m; else l = m; } printf("%.4lf\n", f1(m, y)); } return 0; }