Untitled

#include <iostream>
#include <math.h>
	
double sin_func(double x, double error) {
	double summ = x;
	double term = x;

	int k = 1;
	while (fabs(term) > error) {
		term *= (-1) * x * x / ((2 * k) * (2 * k + 1));
		summ += term;

		k++;
	}
	return summ;
}

double ch_func(double x, double error) {
	double summ = 1;
	double term = 1;

	int k = 1;
	while (fabs(term) > error) {
		term *= (x*x) / (2*k*(2*k-1));

		summ += term;
		k++;
	}
	return summ;
}

double sqrt_func(double a, double error) {
	double prev_x = 0;
	double x = 2;

	while (1) {
		prev_x = x;
		x = (1 / 2.) * (x + a / x);

		if (fabs(x - prev_x) < error) return x;
	}
}

double func(double x) {
	return cosh(sqrt(x * x + 0.3) / (1 + x)) * sin((1 + x) / (0.6 * x));
}

int main() {
	std::cout << "x       my_func                           std_func                          error" << std::endl;

	float c1 = 0.5;
	float c2 = 1.2;
	float c3 = 1;

	double epsilon1 = pow(10, -6) / (3*c1);
	double epsilon2 = pow(10, -6) / (3*c2);
	double epsilon3 = pow(10, -6) / (3*c3);
	
	float x = 0.2;
	for (int i = 0; i < 11; i++) {
		double my_func = ch_func(sqrt_func((x * x + 0.3)/pow(1+x, 2), epsilon1), epsilon3) * sin_func((1 + x) / (0.6 * x), epsilon2);
		double std_func = func(x);
		printf("%.2f    ", x);
		printf("%.20f            ", my_func);
		printf("%.20f            ", std_func);
		printf("%.20f\n", fabs(my_func - std_func));
		
		x += 0.01;
	}
}