#include "stdafx.h"
#include <iostream>
#include <cmath>
#include <conio.h>
using namespace std;

double s(double);

int _tmain(int argc, _TCHAR* argv[])
{
	double a;
	cout<<"Enter a:";
	cin>>a;

	cout<<"Result: "<<s(a);
	getch();
	return 0;
}

double s(double a)
{
	double e = 2.7182;
	//S(a) = 1.2e¯°·¹ª sin (2Π*1000a) при a = 0.0, 0.1 и 0.4. 
	if(a==0.0||a==0.1||a==0.4)
	{
		return (1.2*pow(e,-0.12)*sin(3.1415*1000*a));
	}
}