Volume of cylinder: V = πr²h The desired volume is 1 Liter = 1000 cm³ 1000 = πr²h h = 1000/πr²
Surface area of cylinder: S.A = 2πr² + 2πr²h We substitute the value of h from the first equation: S.A = 2πr² + 2πr(1/πr²) S.A = 2πr² + 2/r Now, to minimize surface area, we differentiate the expression with respect to r and equate to 0. 0 = 4πr - 1000/r² 4πr³ - 1000 = 0 r = 4.3 cm h = 17.2 cm
