Can someone help me solve this calculus problem?

Cost = 1* [ 2 π r h] + 1.6*[2π r²] + [ ?] & 850000 = π r² h + [2/3]π r^3 { solve this for h and put into the cost function}....if the base is to be included then ? = 1* π r ², otherwise ? = 0...now YOU should be able to minimize the cost function