The range of the function f(x) is the set of all values that function f takes.
The domain of the function f(x) is the set of all possible values for x.
From the given graph you can see that the domain is all real numbers,
The maximal y-value that f takes is 3 at x=-1. For all another x from the domain, y is less than 3.
Thus, the range of the given function is
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