The size of an unborn fetus of a certain species depends on its age. Data for Head circumference​ (H) as a function of age​ (t) in weeks were fitted using the formula Upper H equals negative 30.03 plus 1.703 t squared minus 0.7768 t squared log tH=−30.03 1.703t2−0.7768t2logt. ​(a) Calculate the rate of fetal growth StartFraction dH Over dt EndFraction dH dt. ​(b) Is StartFraction dH Over dt EndFraction dH dt larger early in development​ (say at tequals=8 ​weeks) or late​ (say at tequals=36 ​weeks)