Charlie uses the function f(x) = 2x2 + 5x + 3 to track the temperature of a substance, where x represents the time. When you evaluate f(5) you find that the temperature of the substance is 78°C. What is the domain of the situation of Charlie's quadratic function?
THE ANSWER IS D. The domain of the Charlie's function is all real numbers greater than zero. The function alone would have a domain of all real numbers. In the situation given, time cannot be negative, and therefore, cannot be a part of the domain.