Given:

Since, f(x) is defined for all real numbers that are greater than or equal to -3 and less than or equal to 3, the domain of f(x) is [-3, 3].

For any value of x such that -3 ≤ x ≤ 3, the value of f(x) will lie between 0 and 3.

Thus, the range of function is f(x) is [0,3].