Chapter 2.2, Problem 39E

Let D = $\left[\begin{array}{ccc}.005& .002& .001\\ .002& .004& .002\\ .001& .002& .005\end{array}\right]$ be a flexibility matrix, with flexibility measured in inches per pound. Suppose that forces of 30, 50, and 20 lb are applied at points 1, 2, and 3, respectively, in Figure 1 of Example 3. Find the corresponding deflections.