Question

joe is building a wooden cylindrical storage box. the box will have a volume og 6pi m^3. for design purposes, the thick wood for the top and the bottom costs $6/m^2 and the thinner wood for the sides cost $5/m^2.

a)express the cost of the wood as a function of the radius. make sure to simplify the expression.

b) if hoe can afford to spend at most $72pi (~ $226.19) to make the storage box, what are the dimensions of the box?

Answer 1

cost=6*2PIr^2+5*2PIr*h

volume=PIr^2*h or h=volume/PIr^2
cost=12PIr^2+20PIr*6PI/PIr^2

Answer 2

can you please explain how you got these equations?

Answer 3

this is what i got:
cost=6*2PIr^2+5*2PIr*h
= 12PIr^2 + 10PIr*h
= 12PIr^2 + 10PIr*(6/r^2)
= 12PIr^2 + (60PI)/r