```
cvx_begin
variables x(3)
minimize (x(1)^2 + 2*x(1)*x(2) + 2*x(2)^2 + x(3)^2 + 3*x(1) - 4*x(2));
subject to
sqrt(2*x(1)^2 + x(1)*x(2) + 4*x(2)^2 + 4) + (x(1)-x(2)+x(3)+1)^2/(x(1)+x(2)) <= 6;
x >= 1;
cvx_end
```

I am trying to solve this problem. It should be convex. However, after I ran my cvx code, it states “Disciplined convex programming error: Invalid quadratic form(s): not a square.”

Could anyone help me have a look? Any help appreciated!