- A 0 = 2 W = 2 :
function dydt = vdp1s(t,y)
dydt = zeros(2,1); dydt(1) = y(2);
dydt(2) = 1*(1-y(1).^2).*y(2)-2*y(1)+2*sin(2*t);
. 7.
. 7.
6 7
, ():
(1) |
xOy (). () (). (1) :
,
,
.
( , ) (1), , .
(1) , :
(2) |
(1) , :
det A = 0, , , , (2) .
( ) .
, :
(3) |
, a + d = tr A ( ) ad bc = det A.
MATLAB eig(A).
l i ui ≠ 0 ui = l i ui. eig, , :
>> A = [2. 3; 3 5];
>> lam = eig(A)
lam =
0.1459
6.8541
>>
eig .
>> [U, Lam] = eig(A);
, . , ,
>> u1=U(:,1)
u1 =
-0.8507
0.5257
Lam , .
>> Lam
Lam =
0.1459 0
0 6.8541
, , , . :
|
|
>> A*U(:, 2) - Lam(2, 2)*U(:, 2)
ans =
1.0e-015 *
0.4441
-0.8882
, det A ≠ 0, :
(1) :
det A = 0, (1) . :
. , l2 < 0.
t.