Final answer:
The range of the function f(x, y) = 4 - √(4 - x² - y²) is [2, 4].
Step-by-step explanation:
The given function is

To find the range of this function, we need to determine the possible values of f(x, y). Since the square root is only defined for non-negative numbers, the expression inside the square root must be greater than or equal to zero.
So, we have

Rearranging this inequality, we get

This represents a circle with radius 2 centered at the origin. The range of the function is the set of all possible values of f(x, y) for points within this circle.
Thus, the range of the function is [2,4].