can i get help on this

Dhy SCi 3.1.45 mQuestion Help {a An open rectangular box is 3 feet long and has a surface area of 16 square feet. Find the dimensions of the box for which the volume is as large as possible. The width of the box is D feet. 3.2.37 Compute dy dx for y = u 3/2 and u = 8x + 5 using the chain rule formula dy dy du dx du dx The answer isWhen a company.r produces and sells it thousand units per week, its total weekly prot is P thousand dollars, where 400): dP P 2 1002. The production level at t weeks from the present is x = 4 + 2t. Find the marginal prot, a and the time rate + x dP _ _ _ of change of prot: E' Howr fast [With respect of time} are prots changing when t: 8? dP E=D (Type an expression using 2:: as the variable.)