Answer: [tex]x \le -1[/tex]
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Explanation:
The domain is the set of all possible x values of a function.
The largest x can get is x = -1, since this x value applies to the x coordinate of the right most point on the curve. The filled in circle indicates we include this endpoint as part of the domain.
There is no smallest x value due to the arrow showing the curve goes on forever in that direction.
We can write the domain as [tex]-\infty < x \le -1[/tex] but it's better to write [tex]x \le -1[/tex]
Put another way: the domain consists of values that are -1 or smaller.
