Step-by-step explanation:
From the graph, it can be seen that the parabola convers every x-value from the left until at x = -1 and then it stops and continues to x = -1 again but in a straight line all the way to positive infinity.
But notice that at x = -1 form the parabola, the circle dark meaning that it it is included in the domain thus the square bracket and for the straight line as well at x = -1, the circle is not dark meaning it won't be included in the domain.
hopefully this makes sense
:)
