Page 853 - Advanced_Engineering_Mathematics o'neil
P. 853

Answers to Selected Problems  833


                                                                                 10

                                                2
                                                                                  8
                             –1.5   –1    –0.5    0    0.5
                                                                                  6
                                                0
                                                                                y
                                               –2                                 4

                                                                                  2
                                               –4

                                                                                  0
                                               –6                                     8     12     16     20     24
                                                                                                    x
                            FIGURE A.15 Phase portrait for Problem
                                                                                FIGURE A.16 Phase portrait for Problem
                            9, Section 10.6.
                                                                                13(a), Section 10.6.


                                                              10

                                                              8


                                                              6
                                                            y
                                                              4


                                                              2


                                                              0
                                                                0   10  20   30  40  50   60  70
                                                                               x
                                                            FIGURE A.17 Phase  portrait  for  Problem
                                                            13(c), Section 10.6.




                                    √
                             9. −2 ±  3i, spiral point. The solution is
                                                                       √            √
                                                                  −2t          −2t
                                                                c 1 e  cos( 3t) − c 2 e  sin( 3t)
                                                           X =        √             √
                                                               c 1 e −2t  sin( 3t) + 3c 2 e −2t  cos( 3t)
                                Figure A.15 is a phase portrait.
                            11.


                                                        x = ax 1 − bx 1 x 2 − Hx 1 , x =−kx 2 + cx 1 x 2 − Hx 2
                                                         1                 2
                            13. Figure A.16 is a phase portrait for (a), and Figure A.17 for (c).




                      Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
                      Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

                                   October 14, 2010  17:50  THM/NEIL    Page-833        27410_25_Ans_p801-866
   848   849   850   851   852   853   854   855   856   857   858