An open cylinder is to be constructed from a metal sheet so as to hold a given quantity of liquid. Let V and S denote the volume and total surface area of the open cylinder respectively. Based on the information answer the following questions from (i) to (v).
(i) The surface area (S) of the cylinder thus formed expressed as a function of 'r' as
a) b) c) d)(v) The cost of material will be the least
a) When the radius of the cylinder is twice its height.
b) When the height of the cylinder is twice its radius.
c) When the height of the cylinder is thrice its radius.
d) When the height of the cylinder is equal to its radius.