In the study of human metabolism, it is known that daily calorie intake of a person age 25 above primarily affects the variability in weight gain. Scientists conducted an experiment to come up with a working formula of how much will be the average weight y (in kgs.) of a person age 25 if the person regularly has a calories of daily net calorie intake. It was shown that, on the average, y is related to a by the following relationship - In (x + sin? (")] + 50, a> It was also observed that the each year the average weight of a person age 25 changes at a rate 1.5 kgs. per year. How fast is the average daily net calorie intake of a person changing when the person has 4 calories of daily net calorie intake