Вычисление значения функции

#include <iostream>
#include <cmath>
 
using namespace std;
 
int main()
{
 double a = 0.0 , b = 0.0 , y = 0.0;
 
 cout << "Vvedite a= ";
 cin >> a;
 cout << "Vvedite b= ";
 cin >> b;
 
 if(b < a)
  {
   y = (a + b) / (b *b);
  }
 else
  if((a > 0) && (b >= a))
   {
    y = sin(a) + cos(b);
   }
  else y = sqrt(3 * a + b);
 
  cout << "y(" << a << "," << b <<")=" << y << endl;
return 0;
}

#include <iostream>
#include <cmath>
 
using namespace std;
 
int main()
{
    double a, b, y;
 
    cout <<"a="; cin >> a;
    cout <<"b="; cin >> b;
 
    if (b<a&&b!=0) {y=(a+b)/(b*b); cout <<"y="<<y<<endl;}  
    else if (b>=a&&a>0) {y=sin(a)+cos(b); cout <<"y="<<y<<endl;}
    else if (b>=a&&a<=0&&(3*a-b)>=0) {y=sqrt(3*a+b); cout <<"y="<<y<<endl;}
    else cout <<"No solutions\n"; 
    
system("pause");
return 0;
}

y = ((a + b) / (b *b)) - a

#include <iostream>
#include <cmath>
 
using namespace std;
 
int main()
{
    double a, b, y;
 
    cout <<"a="; cin >> a;
    cout <<"b="; cin >> b;
 
    if (b<a&&b!=0) {y=(a+b)/(b*b)-a; cout <<"y="<<y<<endl;}  
    else if (b>=a&&a>0) {y=sin(a)+cos(b); cout <<"y="<<y<<endl;}
    else if (b>=a&&a<=0&&(3*a-b)>=0) {y=sqrt(3*a+b); cout <<"y="<<y<<endl;}
    else cout <<"No solutions\n"; 
    
system("pause");
return 0;
}