A food packet is dropped from a helicopter and is modeled by the function f(x) = −15x2 + 6000. The graph below shows the height f(x), in feet, of the food packet at different times x, in seconds: graph of function f of x equals 6000 minus 15 multiplied by x squared Use the graph to determine the reasonable domain of f(x) based on the context. x ≤ 6000 0 ≤ x ≤ 20 −20 ≤ x ≤ 20 All real numbers