Answer:
a. y = {x+1, x≤2; x+2, x>2}
Explanation:
The open circle at (2, 4) means the function is not defined as y=x+2 at that point. Only one answer selection correctly uses the inequality symbol > for that part of the function definition.
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Comment on the other answer choices.
One selection (b) uses the region definitions x < 2 and x ≥ 2. That would put the open circle at (2, 3) and the filled circle at (2, 4)—not a match with the graph. The other function definitions (c, and d) have the relation defined as two different values at x=2. Such a relation is not a function.