{ xi }, i =0,1, () >0, a 1,, an, a i ³0
xi + + a 1 xi + -1++ an xi = a. (2.21)
(), a =0, (), a ¹0. >0, (x 0,, x -1) . { xi } >0, +1 . F (x)= xn - a 1 xn -1-...- an -1 x - an.
2.1. , (2.21) a =0, .
t , . u
L. M ( det M), .
2.8. { ai (1)},,{ ai ( n )} L Û det M ¹0,
M= . w
a =0 , .. b1,,b n, , .. b =(a 0,, a -1). b=(b1,,b n)
M b= b.
, L.
.
2.3. l - F (x). {l i }={1,l,l2,} (2.21).
t {l i } (2.21). l¹0, :
l i - a 1l i -1-...-l i - n +1 an -1-l i - n an =l i - n (l n - a 1l n -1-...-l an -1- an)= F (l)=0. u
2.9. F (x) n l1,,l n, { },,{ } L.
t 2.3 { },,{ } L. , n , , :
= .
0, , , 2.8 { },,{ } L. u
, n l1,,l n, :
{ xi }=b1{ }++b n { }.
l1,,l n , . , . , , ( 6.5).
|
|
, . F (x) : l1=r(cosj+ i sinj), l2=r(cosj- i sinj).
.
{ }={r j (cos j j+ i sin j j)} { }={r j (cos j j- i sin j j)} {r j cos j j} {r j sin j j}. , .
2.10 [22]. . w