AP:what is the radius of a cylindrical soda can with volume of 512 cubic inches that will usewhat is the radius of a cylindrical soda can with volume of 512 cubic inches that will use the minimum material?
问题描述：
AP:what is the radius of a cylindrical soda can with volume of 512 cubic inches that will use
what is the radius of a cylindrical soda can with volume of 512 cubic inches that will use the minimum material?
答
要求用最少材料做成的圆柱形苏打水桶，能盛512立方英寸苏打水，求水桶最佳半径是多少？
答
V = pi*r^2*h = 512A = 2*pi*r*h + 2*pi*r^2h = 512/(pi*r^2)A = 2*pi*r*512/(pi*r^2) + 2*pi*r^2 = 1024/r + 2*pi*r^2dA/dr = -1024/r^2 + 4*pi*r = 0r = 4.3554 还是要英文翻译?