經濟 - 經濟

學校:東海

科目: 經濟動態分析方法與應用

教科書 Alpha Chiang

題目:
Given a Qutratic Form u'Du, Where D is 2X2

the characteristic equation of D can be written as

| d11-r d12 |
| d21 d22-r| =0 (d12=d21)



Expand the determinant ; express the root of this equation by use of
the qutratic formula; and deduce the following

(a) No imagianry number can occur r1 and r2

(b). to have repeated roots , matrix D must be in the form of [ c 0 ]
[ 0 c ]
(這是一個矩陣)

(c) to have either positive or negatice semidefinateness ,
the discriminant of the quadratic form may vanish , that is,
|D|=o is possibele


我的想法: 請問第一個主要問題 將矩陣的determine值張開
是直接求determine的值嗎

B和C題的題意不大了解 能否請各位高手解釋一下..

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Anything, without blind insistence, is right.

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