Blood flow to the fetal spleen is of research interest because several diseases are associated with increased resistance in the splenic artery. Researchers have found that the index of splenic artery resistance in the fetus can be described by the function
y = 0.057x – 0.001x2,
where x is the number of weeks of gestation.
(a) At how many weeks is the splenic artery resistance a maximum?
(b) What is the maximum splenic artery resistance?
(c) At how many weeks is the splenic artery resistance equal to 0, according to this formula? Is your answer reasonable for this function? Explain.