Let S be the surface area of a cube with edge length L. Homework Help ✎
Write S as a function of L.
If D is the length of the longest diagonal of the cube, write D as a function of L.
Write D as a function of S.
S = 6L2
Draw a triangle within the cube with the longest diagonal D.
Find the diagonal of the bottom square AC.
Solve for L in your equation from part (a) above. Then substitute that expression for L in your D equation.
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