(0 )2 1436587@9BAC9EDGF4HI 7P5QHRFTSVU0DXW6F4H
(0 )2 1436587@9BAC9EDGF4HI 7P5QHRFTSVU0DXW6F4H
(0 )2 1436587@9BAC9EDGF4HI 7P5QHRFTSVU0DXW6F4H
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154 CAPÍTULO 14. ¦£¦£ ££<br />
1 0 2 0<br />
0 1 4 0<br />
0 0 0 1<br />
¢ <br />
¢<br />
§ £ ¡ ¢ ¤£¦¥ § ¢ ©¨<br />
§ ¢ ((1, 0, 2, 0), (0, 1, 4, 0), (0, 0, 0, 1)) ¡ F <br />
dim F =<br />
<br />
3<br />
<br />
1 1 0 0<br />
3 3 0 5<br />
0 0 0 1<br />
<br />
1 1 0 0<br />
3 3 0 5<br />
0 0 0 1<br />
¢ ¢ <br />
<br />
<br />
<br />
−−−−−→<br />
ℓ2 − 3ℓ1<br />
1 1 0 0<br />
0 0 0 5<br />
0 0 0 1<br />
−−−−→<br />
1<br />
5 ℓ2<br />
1 1 0 0<br />
0 0 0 1<br />
0 0 0 1<br />
−−−−→<br />
ℓ2 − ℓ3<br />
G = 〈 (1, 1, 0, 0), (0, 0, 0, 1) 〉 dim G = 2<br />
(a, b, c, d) = (a, b, 2a + 4b, d)<br />
(a, b, c, d) ∈ F ∩ G£¢ (a, b, c, d) ∈ F (a, b, c, d) ∈ G<br />
=⇒<br />
⎧<br />
⎪⎨<br />
⎪⎩<br />
1 1 0 0<br />
0 0 0 1<br />
0 0 0 0<br />
¢¡<br />
(a, b, c, d) = α(1, 1, 0, 0) + β(0, 0, 0, 1) = (α, α, 0, β)<br />
a = b<br />
c = 2a + 4b<br />
c = 0<br />
=⇒ a = b = c = 0<br />
<br />
F ∩ G = {(0, 0, 0, d) | d ∈ IR} = 〈(0, 0, 0, 1)〉 dim F ∩ G = 1<br />
dim(F + G) = dim F + dim G − dim F ∩ G = 4<br />
<br />
¤ A<br />
¡<br />
<br />
<br />
<br />
pA(x) = det (A − xI3) = <br />
<br />
<br />
<br />
= (4 − x) <br />
−4 − x 0<br />
4 4 − x<br />
4 − x 1 2<br />
3 −4 − x 0<br />
− 3<br />
2 4 4 − x<br />
<br />
<br />
−<br />
<br />
<br />
<br />
3 0<br />
− 3<br />
4 − x<br />
2<br />
<br />
<br />
<br />
<br />
<br />
<br />
+ 2 <br />
3 −4 − x<br />
− 3<br />
4 2<br />
= (4 − x)(−4 − x)(4 − x) − 3(4 − x) + 2 12 − 3(4<br />
+ x)<br />
2<br />
= −(4 − x)(4 + x)(4 − x) = −(4 − x) 2 (4 + x)