This is a quadratic equation, which is also a polynomial. Polynomials all have the domain (-infinity, +infinity).
As for the range: You can see from the graph that the smallest y-value is -2. Thus, the range is [-2, infinity).
For this item, we let x be the number of hours she works out and y be the total number of bananas that she will be eating after the workout. The expression that best described the given above is,
y = 5 + 2x
5 is given as the y-intercept because of the initial condition.
