Answer: Choice C. [tex]f(x) \le 1[/tex]
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Reason:
The f(x) represents the y output, and the range is the set of all possible y outputs of a function.
The largest y can get is y = 1, which is at the highest point of the graph, aka the vertex.
We can have y = 1 or y < 1.
Therefore, the range is [tex]y \le 1[/tex] which translates to [tex]f(x) \le 1[/tex]
