### Home > PC3 > Chapter 3 > Lesson 3.1.3 > Problem 3-48

3-48.

Let represent the surface area of a cube with edge length

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Write an equation for

as a function of.A cube has six square sides of length

. What is the area of each square?If

represents the length of the longest diagonal of the cube, write an equation foras a function of.Draw a triangle within the cube with the longest diagonal

.Write an equation for the diagonal of the bottom square

.Write an equation for the longest diagonal,

. Write an equation for

as a function of. Solve for

in your equation from part (a) above. Then substitute that expression forinto yourequation.

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