Formulate the Problem and Solve in Matlab/GAMS

3.7 Design a circular tank, closed at both ends, with a volume of 200m3. The cost is proportional to the surface area of material, which is priced at $400/m2. The tank is contained within a shed with a sloping roof, thus the height of the tank h is limited by h12d/2, where d is the tank diameter. Formulate the minimum cost problem and solve the design