The graph of a function is shown.

"Domain"   is defined as the x values  covered by the graph

Notice that the  least x value  is  -6

And  the arrow indicates that the function covers all the x values from here to infinity

So....the domain   is just  all x values from  -6  to infinity including  x  = -6

In math terms, this can be represented  as

x ≥  -6

Just as Emine has found.....!!!

Does that make sense, RP  ???