1. Calcule o valor de m e n para que as matrizes A e B ... - UTFPR
1. Calcule o valor de m e n para que as matrizes A e B ... - UTFPR
1. Calcule o valor de m e n para que as matrizes A e B ... - UTFPR
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>1.</strong> <strong>Calcule</strong> o <strong>valor</strong> <strong>de</strong> m e n <strong>para</strong> <strong>que</strong> <strong>as</strong> <strong>matrizes</strong> A e B sejam iguais.<br />
[ ] [ ]<br />
m 2 − 40 n 2 + 4<br />
41 13<br />
A =<br />
e B =<br />
.<br />
6 3<br />
6 3<br />
2. Dad<strong>as</strong> <strong>as</strong> <strong>matrizes</strong> A =<br />
calcule:<br />
[<br />
2 3 8<br />
4 −1 −6<br />
] [ ] [<br />
5 −7 −9<br />
0 9 8<br />
, B =<br />
e C =<br />
0 4 1<br />
1 4 6<br />
]<br />
,<br />
(a) A + B<br />
(b) A − C<br />
(c) X = 4A − 3B + 5C.<br />
⎡<br />
⎤ ⎡ ⎤<br />
1 2 3<br />
x 1<br />
3. Efetue a multiplicação d<strong>as</strong> <strong>matrizes</strong> A = ⎢<br />
⎣ −2 −5 7 ⎥<br />
⎦ e X = ⎢<br />
⎣ x 2<br />
⎥<br />
⎦ .<br />
3 9 −8<br />
x 3<br />
⎡ ⎤<br />
1 −2<br />
[ ]<br />
3 1<br />
1 3 −5 −7<br />
4. Dad<strong>as</strong> <strong>as</strong> <strong>matrizes</strong> A =<br />
e B =<br />
, calcule:<br />
⎢<br />
⎣<br />
7 −4 ⎥<br />
⎦<br />
6 2 −8 3<br />
5 9<br />
(a) A.B<br />
(b) B.A<br />
5. Nos exercícios abaixo, verifi<strong>que</strong> se a matriz B é a inversa da matriz A:<br />
⎡<br />
⎤ ⎡<br />
⎤<br />
−2 −4 −6<br />
− 3 (a) A = ⎢<br />
⎣ −4 −6 −6 ⎥<br />
⎦ e B = 2<br />
2 − 3 2<br />
⎢<br />
⎣ 2 − 5 3 ⎥<br />
2 2 ⎦<br />
−4 −4 −2<br />
−1 1 − 1 2<br />
⎡<br />
⎤ ⎡<br />
⎤<br />
4 5 0<br />
9 3 4<br />
(b) A = ⎢<br />
⎣ 2 3 0 ⎥<br />
⎦ e B = ⎢<br />
⎣ −7 2 5 ⎥<br />
⎦ .<br />
−6 −1 −2<br />
1 6 8<br />
6. <strong>Calcule</strong> os <strong>valor</strong>es <strong>de</strong> m e n <strong>para</strong> <strong>que</strong> a matriz B seja a inversa da matriz A.<br />
[ ] [ ]<br />
m −22<br />
5 22<br />
A =<br />
e B =<br />
−2 n<br />
2 9<br />
1
⎡<br />
7. Dad<strong>as</strong> <strong>as</strong> <strong>matrizes</strong> A =<br />
⎢<br />
⎣<br />
(AB) T .<br />
5 0 6<br />
−8 0 3<br />
−2 2 7<br />
1 −1 −5<br />
⎤<br />
⎥<br />
⎦<br />
e B =<br />
⎡<br />
⎢<br />
⎣<br />
1 −3 −2 4<br />
7 8 5 9<br />
0 6 3 −8<br />
⎤<br />
⎥<br />
⎦ , calcule<br />
8. Dad<strong>as</strong> <strong>as</strong> matirzes:<br />
[ ] [<br />
0 1<br />
6 9<br />
A = , B =<br />
1 0 −4 −6<br />
] [<br />
5 10<br />
, C =<br />
−2 −4<br />
]<br />
e D =<br />
⎡<br />
⎢<br />
⎣<br />
−1 2 6<br />
3 −2 −9<br />
−2 0 3<br />
⎤<br />
⎥<br />
⎦<br />
(a) <strong>Calcule</strong> A.A T<br />
(c) <strong>Calcule</strong> C 2<br />
(b) <strong>Calcule</strong> B 2 (d) <strong>Calcule</strong> D 3<br />
⎡<br />
⎤ ⎡<br />
⎤<br />
3 4 1<br />
4 −1 3<br />
9. Dad<strong>as</strong> <strong>as</strong> <strong>matrizes</strong> A = ⎢<br />
⎣ −5 −2 −9 ⎥<br />
⎦ e B = ⎢<br />
⎣ 3 0 1 ⎥<br />
⎦ , calcule:<br />
7 8 6<br />
7 2 −4<br />
(a) <strong>de</strong>tA<br />
(b) <strong>de</strong>tB<br />
(c) <strong>de</strong>t(A + B)<br />
10. Verifi<strong>que</strong>, usando o exercício anterior, se <strong>de</strong>t(A + B) = <strong>de</strong>tA + <strong>de</strong>tB.<br />
⎡<br />
⎤<br />
−2 3 1 −1<br />
0 1 2 3<br />
1<strong>1.</strong> <strong>Calcule</strong> o <strong>de</strong>terminante da matriz A =<br />
.<br />
⎢<br />
⎣<br />
1 −1 1 −2 ⎥<br />
⎦<br />
4 −3 5 1<br />
5 1 3<br />
12. Resolva a equação<br />
3x 0 1<br />
= 100.<br />
∣ 7x 2 1 ∣<br />
13. Encontre a inversa d<strong>as</strong> seguintes <strong>matrizes</strong>:<br />
[ ]<br />
3 5<br />
(a) A =<br />
1 2<br />
⎡<br />
⎤<br />
1 0 0 0<br />
2 1 0 0<br />
(b) A =<br />
⎢<br />
⎣<br />
3 2 1 0 ⎥<br />
⎦<br />
4 3 2 1<br />
(c) A =<br />
(d) A =<br />
⎡<br />
⎢<br />
⎣<br />
⎡<br />
⎢<br />
⎣<br />
2 2 2<br />
3 4 7<br />
1 2 5<br />
2 0 0<br />
0 3 0<br />
0 0 7<br />
⎤<br />
⎥<br />
⎦<br />
⎤<br />
⎥<br />
⎦<br />
2
14. Cl<strong>as</strong>sifi<strong>que</strong> e resolva os sistem<strong>as</strong>:<br />
{<br />
5x + 8y = 34<br />
(a)<br />
10x + 16y = 50<br />
⎧<br />
⎪⎨ 4x − y − 3z = 15<br />
(b) 3x − 2y + 5z = −7<br />
⎪⎩<br />
2x + 3y + 4z = 7<br />
{<br />
x + 4y + 6z = 0<br />
(c)<br />
− 3 2<br />
− 6y − 9z = 0<br />
(d)<br />
⎧<br />
⎪⎨ x + 4y + 6z = 11<br />
2x + 3y + 4z = 9<br />
⎪⎩<br />
3x + 2y + 2z = 7<br />
⎧<br />
⎪⎨ 2x + 2y + 4z = 0<br />
(e) 3x + 5y + 8z = 0<br />
⎪⎩<br />
5x + 25y + 20z = 0<br />
15. Encontre o <strong>valor</strong> dos termos in<strong>de</strong>pen<strong>de</strong>ntes <strong>para</strong> <strong>que</strong> o sistema tenha solução:<br />
⎧<br />
⎪⎨ 4x + 12y + 8z = a<br />
2x + 5y + 3z = b<br />
⎪⎩<br />
−4y − 4z = c<br />
16. Resolva os sistem<strong>as</strong> abaixo pelo método matricial:<br />
⎧<br />
−2x 1 − x 2 + 2x 4 = b 1<br />
⎪⎨<br />
3x 1 + x 2 − 2x 3 − 2x 4 = b 2<br />
⎪⎩<br />
−4x 1 − x 2 + 2x 3 + 3x 4 = b 3<br />
3x 1 + x 2 − x 3 − 2x 4 = b 4<br />
(a) b 1 = 5, b 2 = 3, b 3 = 12 e b 4 = 10<br />
(b) b 1 = −8, b 2 = −4, b 3 = −9 e b 4 = 8<br />
(c) b 1 = 4, b 2 = 0, b 3 = −2 e b 4 = 3<br />
(d) b 1 = −9, b 2 = 6, b 3 = 3 e b 4 = 1<br />
Respost<strong>as</strong> dos exercícios<br />
<strong>1.</strong> m = ±9 e n = ±3<br />
2. (a)<br />
3. A.X =<br />
[<br />
7 −4 −1<br />
4 3 −5<br />
⎡<br />
⎢<br />
⎣<br />
]<br />
x 1 + 2x 2 + 3x 3<br />
−2x 1 − 5x 2 + 7x 3<br />
3x 1 + 9x 2 − 8x 3<br />
(b)<br />
⎤<br />
⎥<br />
⎦ .<br />
⎡<br />
⎤<br />
−11 −1 11 −13<br />
9 11 −23 −18<br />
4. (a)<br />
⎢<br />
⎣<br />
−17 13 1 −61 ⎥<br />
⎦<br />
59 33 −97 −8<br />
[<br />
2 −6 0<br />
3 −5 −12<br />
(b)<br />
]<br />
(c)<br />
[<br />
−60 −42<br />
−29 49<br />
[<br />
−7 78 99<br />
]<br />
21 4 3<br />
]<br />
3
5. (a) sim (b) não<br />
6. m = 9 e n = 5<br />
⎡<br />
5 −8 12 −6<br />
21 42 64 −41<br />
7.<br />
⎢<br />
⎣<br />
8 25 35 −22<br />
−28 −56 −46 35<br />
[ ]<br />
1 0<br />
8. (a)<br />
0 1<br />
[ ]<br />
0 0<br />
(b)<br />
0 0<br />
⎤<br />
⎥<br />
⎦<br />
[ ]<br />
5 10<br />
(c)<br />
−2 −4<br />
⎡<br />
⎤<br />
−1 2 6<br />
(d) ⎢<br />
⎣ 3 −2 −9 ⎥<br />
⎦<br />
−2 0 3<br />
9. (a) 22<br />
(b) −9<br />
(c) 240<br />
10. Não<br />
1<strong>1.</strong> 2<br />
12. x = 5<br />
[ ]<br />
2 −5<br />
13. (a) A −1 =<br />
−1 3<br />
⎡<br />
1 0 0 0<br />
(b) A −1 −2 1 0 0<br />
=<br />
⎢<br />
⎣<br />
1 −2 1 0<br />
0 1 −2 1<br />
⎤<br />
⎥<br />
⎦<br />
(c) A não tem inversa<br />
⎡ ⎤<br />
1<br />
2<br />
0 0<br />
(d) A −1 = ⎢ 1<br />
⎣ 0<br />
3<br />
0 ⎥<br />
⎦<br />
1<br />
0 0<br />
7<br />
14. (a) o sistema é incompatível<br />
(b) o sistema é compatível e <strong>de</strong>terminado: x = 3, y = 3 e z = −2<br />
(c) o sistema é compatível e in<strong>de</strong>terminado: grau <strong>de</strong> liberda<strong>de</strong> g = 2<br />
solução trivial: x = y = z = 0<br />
soluções própri<strong>as</strong>: x = −4y − 6z<br />
(d) o sistema é compatível e in<strong>de</strong>terminado: grau <strong>de</strong> liberda<strong>de</strong>: g=1<br />
x = 3+2z<br />
5<br />
e y = 13−8z<br />
5<br />
(e) o sistema é compatível e <strong>de</strong>terminado: admite apen<strong>as</strong> a solução trivial: x =<br />
y = z = 0<br />
4
15. 2a − 4b + c = 0<br />
16. (a) x 1 = 22, x 2 = 25, x 3 = 7 e x 4 = 37<br />
(b) x 1 = 12, x 2 = −18, x 3 = 12 e x 4 = −1<br />
(c) x 1 = 10, x 2 = −8, x 3 = 3 e x 4 = 8<br />
(d) x 1 = −13, x 2 = 27, x 3 = −5 e x 4 = −4<br />
5