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A 20 cm long, 16 cm wide rectangular sheet iron, four corners of each cut off the length of 4cm small square, make a no cover box. Find the volume of the box It's due tomorrow
(20-8) * (16-8) * 4 = 384 cm3
As shown in the figure, cut a square of the same size around a rectangular cardboard of 10 cm long and 8 cm wide, and then convert it into a cuboid box without cover (the thickness of the cardboard is ignored)
(1) To make the bottom area of the cuboid box 48cm2, what is the side length of the cut square; (2) do you feel that the side area of the converted cuboid box will be larger? If yes, please find out the maximum value and the side length of the square cut out at this time; if not, please explain the reason; (3) if you cut out two squares of the same size and two rectangles of the same shape and size around the rectangular cardboard respectively, and then convert them into a rectangular box with a cover, is there a case of the largest side area? If yes, please find out the maximum value and the side length of the cut square; if not, please explain the reason
(1) Let the side length of the square be xcm, then (10-2x) (8-2x) = 48. That is, x2-9x + 8 = 0. The solution is X1 = 8 (not suitable for the problem, rounding off), X2 = 1. The side length of the cut square is 1cm. (2) there is the case of the largest side area. Let the side length of the square be xcm, and the side area of the box be ycm2, then the function of Y and X
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