To make a cuboid water tank without a cover, the side length of the bottom of the water tank is 6 decimeters square, 2 meters, which is necessary to make such a water tank (Continued) how many square decimeters of iron sheet? How many liters of water can it hold? (note conversion)

To make a cuboid water tank without a cover, the side length of the bottom of the water tank is 6 decimeters square, 2 meters, which is necessary to make such a water tank (Continued) how many square decimeters of iron sheet? How many liters of water can it hold? (note conversion)

1.2 m = 12 decimeters
Iron sheet required = (6 * 6 + 6 * 12 + 6 * 12) * 2-6 * 6 = 324 square decimeters
Volume = 6 * 6 * 12 = 432 liters

Make a 256 liter square bottomed open water tank (the bottom is square), then its height is______ &The material is the most economical

Let the height of the tank be x, and the length of the bottom edge be a, then a2x = 256, and its surface area s = 4ax + A2 = 4A × 256a2 + A2 = 1024a + A2 = 512a + 512a + A2 ≥ 33512a × 512a × A2 = 3 × 26 = 192. If and only if a = 8, that is, H = 25682 = 4, s gets the minimum value

Make a 256 liter square bottomed open water tank (the bottom is square), then its height is______ &The material is the most economical

Let the height of the tank be x, and the length of the bottom edge be a, then a2x = 256, and its surface area s = 4ax + A2 = 4A × 256a2 + A2 = 1024a + A2 = 512a + 512a + A2 ≥ 33512a × 512a × A2 = 3 × 26 = 192. If and only if a = 8, that is, H = 25682 = 4, s gets the minimum value