20.06.2013 Views

pdf (it, 2.898,97 KB, 25/01/13)

pdf (it, 2.898,97 KB, 25/01/13)

pdf (it, 2.898,97 KB, 25/01/13)

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Φ y ′ = A(t) <br />

y ′ = A(t)y + b(t) u(0) = y0 <br />

u(t) = R(t, t0)y0 +<br />

t<br />

t0<br />

R(t, τ)b(τ) dτ<br />

Φ R(t, τ) = Φ(t)Φ −1 (τ)<br />

<br />

n <br />

y (n) + ... + any = Q(x)<br />

y(x) = c1y1(x) + ... + cnyn(x) ck ∈ R <br />

ck ck = ck(x) n n c ′ k (x)<br />

⎧<br />

⎪⎨<br />

<br />

⎪⎩<br />

c ′ 1 (x)y1(x) + ... + c ′ n(x)yn(x) = 0,<br />

c ′ 1 (x)y′ 1 (x) + ... + c′ n(x)y ′ n(x) = 0,<br />

c ′ 1 (x)y(n−1) 1 (x) + ... + c ′ n(x)y (n−1)<br />

n (x) = 0,<br />

c ′ 1 (x)y(n) 1 (x) + ... + c′ n(x)y (n)<br />

n (x) = Q(x).<br />

<br />

⎛<br />

y1(x)<br />

⎜ y<br />

⎜<br />

⎝<br />

... yn(x)<br />

′ 1 (x) ... y′ <br />

y<br />

n(x)<br />

<br />

(n−1)<br />

⎞ ⎛<br />

⎟ ⎜<br />

⎟ ⎜<br />

⎟ ⎜<br />

⎟ ⎜<br />

⎟ ⎜<br />

(x) ⎠ ⎝<br />

1 (x) ... y (n−1)<br />

n<br />

y (n)<br />

1<br />

(x) ... y(n)<br />

n (x)<br />

c ′ 1 (x)<br />

c ′ 2 (x)<br />

<br />

c ′ n−1<br />

c ′ n<br />

⎞<br />

⎛<br />

⎟ ⎜<br />

⎟ ⎜<br />

⎟ ⎜<br />

⎟ = ⎜<br />

⎟ ⎜<br />

⎠ ⎝<br />

0<br />

0<br />

<br />

0<br />

Q(x)<br />

y1(x), ..., yn(x) <br />

c ′ k (x) ck(x) <br />

<br />

¯y(x) = c1(x)y1(x) + ... + cn(x)yn(x),<br />

<br />

y(x) + ¯y(x) = (c1(x) + c1)y1(x) + ... + (cn(x) + cn)yn(x), c1, ..., cn ∈ R.<br />

<br />

y ′′ + a(t)y ′ + b(t)y = f(t),<br />

<br />

˜y = c1(t)y1(t) + c2(t)y2(t)<br />

y1(t) y2(t) <br />

y ′′ + a(t)y ′ + b(t)y = 0.<br />

<br />

˜y ′ = c ′ 1y1 + c ′ 2y2 + c1y ′ 1 + c2y ′ 2.<br />

c ′ 1y1 + c ′ 2y2 = 0 ˜y ′ = c1y ′ 1 + c2y ′ 2 <br />

<br />

˜y ′′ = c ′ 1y ′ 1 + c ′ 2y ′ 2 + c1y ′′<br />

1 + c2y ′′<br />

2.<br />

<br />

<br />

(c ′ 1y ′ 1 + c ′ 2y ′ 2 + c1y ′′<br />

1 + c2y ′′<br />

2) + a(c1y ′ 1 + c2y ′ 2) + b(c1y1 + c2y2) = f<br />

c1(y ′′<br />

1 + ay ′ 1 + by1) + c2(y ′′<br />

2 + ay ′ 2 + by2) + (c ′ 1y ′ 1 + c ′ 2y ′ 2) = f.<br />

⎞<br />

⎟<br />

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!