The (m 1) x (m 1) tridiagonal matrix 1 +2ff A = a 0 a 1 + 2a O;; ff 0 0' 0 a a 1 + 2a is involved in the Backward Difference method to solve the heat equation. (See Section 12.2.) For the stability ofthe method, we need p(A -1) < I. With m = 11, approximate p(A~l ) for each of the following. a. b. c. a = | When is the method stable?

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