You multiply 3.14 by the diameter or 2 times the radius
for area you do pi or 3.14*radius squared
I think you want to write it
so it's:
9-1/3
Assuming R and H:
So volume is pir^2 * H = 1500 and H = 1500/(pir^2) while surface area is A= 2pir*H + 2pir^2
A = 2pir(r+h)= 2piR^2 + 2pir*1500/(pir^2)= 2piR^2 + 3000/r
For A to take minimum, get the derivative 4pir - 3000/R^2 and let it be 0
4pir^3 - 3000 = 0
r = cbrt(3000/(4pi)) ≈ 6.20
h = 1500/(pi(6.20)^2) ≈ 12.42
Bring the 3 to the other side, which makes 11-3 = 8
divide the whole equation by 2, which makes it Root (3x/5) = 8/2
square the whole equation which gives
, 3x/5 = 16
Multiply the equation by 5 which makes it, 3x = 80
finally divide the equation to find x, x= 80/3