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发帖数: 260 | 1 Show that the qudratic equation z^2+bz+c=0 with the roots lies in or on the
unit circle if and only if |c|<=1 and |b|<=1+c.
I have showed the necessary condition, but I have no idea of the sufficient
condition part.
Would any people like to help me?
Also, this is the first question in one problem. The second and the third one
ask to show that some shceme is stable. It is not difficult for the second
question if I can get the first proof. But there is a small gap in this part.
I would like to pos |
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