A rectangular beam will be cut from a cylindrical log of diameter 1m.
For part a) I have shown that the beam of maximal cross-sectional area is a square.
Then 4 rectangular planks will be cut from the 4 sections of the log that remains after cutting the square beam. Determine the dimensions of the planks that will have maximal cross-sectional area.
So here's what I think: Let x be the width of the rectangular planks and y be the length of the rectangular planks.
Then the Area of one rectangular plank= xy
From part a) The maximal cross-sectional area is 0.5m^2
How do I proceed after this ?