A manufacturing firm wants to package its product in a cylindrical container 2ft high with a surface area of 6 what is the radius

Answer 1

surface area = 2pi(r)^2 + 2pir(2) = 6

= area of the circular top & bottom + circumference x height

divide by 2pi to get

r^2 + 2r = 6/2pi = 3/pi = 0.955

complete the square by adding 1 to both sides

r^2 + 2r + 1 = 3/pi + 1 = .955 + 1

(r+1)^2 = .955 + 1 = 1.955 = (1.4)^2

r = -1 + or - sqr(1.955) = -1 + 1.4 inches = .4 inch radius