Page 159 - Schaum's Outline of Differential Equations
P. 159

142                                        e At                                 [CHAP.  16





                    M
         16.2.  Find e  for  A =
                  Since n = 2, it follows from Eqs. (16.3)  and (16.5) that





              and r (X) =  c^X + a 0. The eigenvalues of At are Xj = 2t and X 2 = -4f, which are both of multiplicity one. Substituting
              these values successively into (16.6),  we obtain



               Solving these equations for a : and a a, we find  that




               Substituting these values into (1) and simplifying,  we have







                    At
         16.3.  Find e  for  A =

                  Here n = 2; hence,




              and r(k)  = cqX + a 0. The  eigenvalues of At  are Xj = it and  X 2 = —it, which are both of multiplicity one. Substituting
              these values successively into Eq.  (16.6),  we obtain


               Solving these equations for a : and a 0 and using Euler's  relations, we find  that








               Substituting these values into  (_/), we  obtain







         16.4.  Find e^' for A =

                  Here n = 2. From  Eq.  (16.3),
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