// ВАРИАНТ 26
//

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

using namespace std;

double getFunctionResult(double x, double a) {
	return (2 * x / (sqrt(0.2 * a + cos(x / 2 + a))));
}

int main() {
	setlocale(LC_ALL, "Russian");

	char arr[] = "ОШИБКА!";
	const double X = -0.9, XX = 4.1, XXX = 0.5;
	double a, x;
	int L = (XX - X) / XXX;

	x = X;

	cout << "ВВЕДИТЕ A: \n ";
	cin >> a;

	printf("-----------------------------------------------------------\n");
	printf("  |     A      |          FUNCTION       |       X        |\n");
	printf("-----------------------------------------------------------\n");

	for (int k = 0; k < L; k = k + 1) {
  	while (x != XX) {
			if (2 * x / (sqrt(0.2 * a + cos(x / 2 + a))) == 0) {
				printf("|  %6.2f  | %25.2s | %17.5s |\n", a, x, arr);
			} else {
				printf("|  %6.2f  | %25.2f | %17.5f |\n", a, x, getFunctionResult(x, a));
			}

			x = x + XXX;
  		}
	}

	printf("-----------------------------------------------------------\n");
	return 0;
}