Algebra

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Valori proprii ale sumei a doua matrice

Last post by Radu Titiu « Sat May 31, 2008 11:57 am
Replies: 3
by Bogdan Cebere » Tue May 13, 2008 6:04 pm

3 Replies

1431 Views

Last post by Radu Titiu
Sat May 31, 2008 11:57 am
Concursul 'Gh. Titeica', Problema 1

Last post by Marius Dragoi « Fri May 23, 2008 9:58 pm

by Marius Dragoi » Fri May 23, 2008 9:58 pm

0 Replies

948 Views

Last post by Marius Dragoi
Fri May 23, 2008 9:58 pm
Inegalitatea lui Schur pentru valorile proprii

Last post by Bogdan Posa « Tue May 20, 2008 4:17 pm
Replies: 1
by bogdanl_yex » Mon May 19, 2008 9:42 pm

1 Replies

1098 Views

Last post by Bogdan Posa
Tue May 20, 2008 4:17 pm
Concursul 'Marian Tarina' 2008 pb 1

Last post by Radu Titiu « Mon May 19, 2008 1:54 pm
Replies: 2
by Radu Titiu » Mon May 19, 2008 1:35 pm

2 Replies

897 Views

Last post by Radu Titiu
Mon May 19, 2008 1:54 pm
Invertible matrix of even size

Last post by Beniamin Bogosel « Sat May 17, 2008 11:27 am
Replies: 1
by o.m. » Sat May 17, 2008 10:31 am

1 Replies

828 Views

Last post by Beniamin Bogosel
Sat May 17, 2008 11:27 am
Matrix equation

Last post by o.m. « Sat May 17, 2008 11:07 am

by o.m. » Sat May 17, 2008 11:07 am

0 Replies

756 Views

Last post by o.m.
Sat May 17, 2008 11:07 am
Density of invertible matrices

Last post by o.m. « Sat May 17, 2008 11:03 am

by o.m. » Sat May 17, 2008 11:03 am

0 Replies

822 Views

Last post by o.m.
Sat May 17, 2008 11:03 am
Problema 2 ONM 2008

Last post by Radu Titiu « Thu May 01, 2008 8:31 am

by Radu Titiu » Thu May 01, 2008 8:31 am

0 Replies

913 Views

Last post by Radu Titiu
Thu May 01, 2008 8:31 am
Problema cu matrice (IMC 2000)

Last post by Radu Titiu « Mon Apr 21, 2008 5:56 pm
Replies: 1
by Centea Andrei » Mon Apr 21, 2008 4:09 pm

1 Replies

926 Views

Last post by Radu Titiu
Mon Apr 21, 2008 5:56 pm
Functii polinomiale injective pe mult. matricelor de ordin 2

Last post by dina013 « Sun Apr 20, 2008 8:50 pm
Replies: 1
by Bogdan Cebere » Fri Apr 11, 2008 2:58 pm

1 Replies

932 Views

Last post by dina013
Sun Apr 20, 2008 8:50 pm
Concursul "Al. Myller" problema 1

Last post by Radu Titiu « Mon Apr 14, 2008 11:16 am
Replies: 1
by Bogdan Cebere » Sun Apr 13, 2008 10:34 pm

1 Replies

925 Views

Last post by Radu Titiu
Mon Apr 14, 2008 11:16 am
Concursul "Al. Myller" problema 2

Last post by Radu Titiu « Sun Apr 13, 2008 10:56 pm
Replies: 2
by Bogdan Cebere » Sun Apr 13, 2008 10:35 pm

2 Replies

1135 Views

Last post by Radu Titiu
Sun Apr 13, 2008 10:56 pm
Matrice inversabile "incrucisate"

Last post by Dragos Fratila « Sat Apr 12, 2008 11:18 am

by Dragos Fratila » Sat Apr 12, 2008 11:18 am

0 Replies

687 Views

Last post by Dragos Fratila
Sat Apr 12, 2008 11:18 am
AB+BA=O si AX+XA=B implica B nilpotenta

Last post by bae « Thu Apr 10, 2008 12:28 am
Replies: 5
by Bogdan Posa » Tue Apr 08, 2008 6:15 pm

5 Replies

1577 Views

Last post by bae
Thu Apr 10, 2008 12:28 am
O alta matrice singulara...

Last post by Beniamin Bogosel « Fri Apr 04, 2008 3:38 pm
Replies: 2
by bogdanl_yex » Thu Apr 03, 2008 11:12 pm

2 Replies

1065 Views

Last post by Beniamin Bogosel
Fri Apr 04, 2008 3:38 pm
Matrice cu elemente numere reale si det-ul zero

Last post by bogdanl_yex « Thu Apr 03, 2008 7:45 pm
Replies: 10
by bogdanl_yex » Thu Apr 03, 2008 12:43 pm

10 Replies

2736 Views

Last post by bogdanl_yex
Thu Apr 03, 2008 7:45 pm
Ordinul unei matrice...

Last post by Radu Titiu « Fri Mar 28, 2008 9:22 pm
Replies: 1
by Lavinia » Fri Mar 28, 2008 12:04 am

1 Replies

890 Views

Last post by Radu Titiu
Fri Mar 28, 2008 9:22 pm
Rolle si determinanti

Last post by c.adryan « Tue Mar 25, 2008 8:33 pm
Replies: 2
by c.adryan » Mon Mar 24, 2008 10:09 pm

2 Replies

1070 Views

Last post by c.adryan
Tue Mar 25, 2008 8:33 pm
Matrice de ordin 4 cu elemente intregi si A^3=A+I_n

Last post by Marius Dragoi « Tue Mar 25, 2008 10:12 am
Replies: 1
by Cezar Lupu » Mon Nov 05, 2007 2:05 am

1 Replies

926 Views

Last post by Marius Dragoi
Tue Mar 25, 2008 10:12 am
O problema cu permutari

Last post by Beniamin Bogosel « Mon Mar 24, 2008 5:38 pm
Replies: 1
by Bogdan Posa » Mon Mar 24, 2008 12:59 pm

1 Replies

712 Views

Last post by Beniamin Bogosel
Mon Mar 24, 2008 5:38 pm
Suma elementelor dintr-o matrice

Last post by Beniamin Bogosel « Mon Mar 24, 2008 3:28 pm
Replies: 1
by bogdanl_yex » Sat Mar 22, 2008 2:05 pm

1 Replies

691 Views

Last post by Beniamin Bogosel
Mon Mar 24, 2008 3:28 pm
Matrice cu determinant pozitiv

Last post by Cezar Lupu « Sat Mar 22, 2008 5:49 pm
Replies: 3
by bogdanl_yex » Sat Mar 22, 2008 1:33 pm

3 Replies

965 Views

Last post by Cezar Lupu
Sat Mar 22, 2008 5:49 pm
Conditie suficienta pentru o matrice astfel incat A^3=O_3

Last post by Beniamin Bogosel « Fri Mar 21, 2008 11:45 am
Replies: 2
by Cezar Lupu » Mon Jan 21, 2008 11:13 pm

2 Replies

1341 Views

Last post by Beniamin Bogosel
Fri Mar 21, 2008 11:45 am
O matrice cu urma puterilor nula este nilpotenta

Last post by Beniamin Bogosel « Fri Mar 21, 2008 11:33 am
Replies: 1
by Cezar Lupu » Mon Mar 17, 2008 12:08 am

1 Replies

1569 Views

Last post by Beniamin Bogosel
Fri Mar 21, 2008 11:33 am
Inegalitate cu rang si exista matrice inversabila

Last post by Radu Titiu « Thu Mar 20, 2008 12:45 pm
Replies: 3
by Madalina » Sun Mar 02, 2008 9:07 am

3 Replies

1779 Views

Last post by Radu Titiu
Thu Mar 20, 2008 12:45 pm
AB si BA au acelasi polinom caracteristic

Last post by Radu Titiu « Thu Mar 20, 2008 9:57 am
Replies: 2
by Alin Galatan » Sun Jan 13, 2008 3:23 pm

2 Replies

1196 Views

Last post by Radu Titiu
Thu Mar 20, 2008 9:57 am
Matrice simetrica reala cu cel mult 10 elemente negative

Last post by Beniamin Bogosel « Wed Mar 19, 2008 10:23 pm
Replies: 2
by bae » Wed Mar 12, 2008 5:50 pm

2 Replies

854 Views

Last post by Beniamin Bogosel
Wed Mar 19, 2008 10:23 pm
Pentru doua matrice X, Y avem rank(XY)-rank(YX)<=[n/2]

Last post by Beniamin Bogosel « Tue Mar 18, 2008 9:22 pm
Replies: 4
by Cezar Lupu » Fri Nov 02, 2007 6:18 am

4 Replies

1197 Views

Last post by Beniamin Bogosel
Tue Mar 18, 2008 9:22 pm
Matrice inversabila

Last post by Alin Galatan « Tue Mar 11, 2008 9:22 pm
Replies: 1
by Marius Dragoi » Tue Mar 11, 2008 3:06 pm

1 Replies

842 Views

Last post by Alin Galatan
Tue Mar 11, 2008 9:22 pm
SEEMOUS 2008, problema 3

Last post by aleph « Mon Mar 10, 2008 5:19 pm
Replies: 1
by Alin Galatan » Fri Mar 07, 2008 5:09 pm

1 Replies

1528 Views

Last post by aleph
Mon Mar 10, 2008 5:19 pm
Matrice cu determinantul strict pozitiv

Last post by Radu Titiu « Sat Mar 08, 2008 10:53 pm
Replies: 1
by Cezar Lupu » Sat Mar 08, 2008 10:02 pm

1 Replies

762 Views

Last post by Radu Titiu
Sat Mar 08, 2008 10:53 pm
Inegalitate cu determinanti

Last post by Marius Dragoi « Tue Mar 04, 2008 9:00 pm
Replies: 4
by Madalina » Sun Mar 02, 2008 8:53 am

4 Replies

1783 Views

Last post by Marius Dragoi
Tue Mar 04, 2008 9:00 pm
Doua matrice de ordin 3 diferite

Last post by Ciprian Oprisa « Sat Mar 01, 2008 11:04 pm
Replies: 1
by Cezar Lupu » Fri Nov 09, 2007 10:59 pm

1 Replies

826 Views

Last post by Ciprian Oprisa
Sat Mar 01, 2008 11:04 pm
Matrice cu valorile proprii strict pozitive

Last post by Ciprian Oprisa « Sat Mar 01, 2008 8:01 pm
Replies: 1
by Cezar Lupu » Mon Nov 12, 2007 1:22 am

1 Replies

773 Views

Last post by Ciprian Oprisa
Sat Mar 01, 2008 8:01 pm
det(I+A)>=1 pentru matrice antisimetrica

Last post by Ciprian Oprisa « Sat Mar 01, 2008 7:34 pm
Replies: 1
by Diana Putan » Sun Dec 09, 2007 2:35 pm

1 Replies

1093 Views

Last post by Ciprian Oprisa
Sat Mar 01, 2008 7:34 pm
Matrice ordin 3 cu det(A^2+I_3)=0

Last post by Ciprian Oprisa « Wed Feb 20, 2008 10:08 am
Replies: 1
by Cezar Lupu » Tue Feb 05, 2008 1:37 am

1 Replies

842 Views

Last post by Ciprian Oprisa
Wed Feb 20, 2008 10:08 am
Inegalitate cu determinanti si numere complexe de modul 1

Last post by bae « Tue Feb 19, 2008 10:25 pm
Replies: 2
by bae » Mon Feb 18, 2008 3:49 am

2 Replies

907 Views

Last post by bae
Tue Feb 19, 2008 10:25 pm
Matrice ordin 3 cu urma lui A si A^2 nula

Last post by Radu Titiu « Sun Feb 10, 2008 11:20 pm
Replies: 1
by Cezar Lupu » Tue Feb 05, 2008 1:32 am

1 Replies

709 Views

Last post by Radu Titiu
Sun Feb 10, 2008 11:20 pm
Matrice cu elemente din {0,1}

Last post by Cezar Lupu « Sun Feb 10, 2008 1:00 am
Replies: 2
by Alex Dura » Wed Oct 24, 2007 10:09 pm

2 Replies

1136 Views

Last post by Cezar Lupu
Sun Feb 10, 2008 1:00 am
det(A^2+B^2)\geq det(AB-BA)

Last post by Bogdan Posa « Fri Feb 08, 2008 12:55 pm
Replies: 3
by Cezar Lupu » Mon Oct 15, 2007 9:29 pm

3 Replies

1310 Views

Last post by Bogdan Posa
Fri Feb 08, 2008 12:55 pm
Matrice similare

Last post by aleph « Fri Feb 08, 2008 10:44 am
Replies: 1
by maky » Wed Oct 10, 2007 5:54 pm

1 Replies

1014 Views

Last post by aleph
Fri Feb 08, 2008 10:44 am
det(A^4+I_n) diferit de 13

Last post by bae « Wed Feb 06, 2008 9:25 pm
Replies: 2
by Cezar Lupu » Mon Feb 04, 2008 8:48 pm

2 Replies

977 Views

Last post by bae
Wed Feb 06, 2008 9:25 pm
Matrice rationala de ordinul 2 cu A^3+A=I_2

Last post by Marius Dragoi « Thu Jan 31, 2008 11:06 pm
Replies: 2
by Cezar Lupu » Sun Dec 23, 2007 12:25 pm

2 Replies

1030 Views

Last post by Marius Dragoi
Thu Jan 31, 2008 11:06 pm
Matrice de ordin 2 nilpotenta

Last post by Radu Titiu « Mon Jan 28, 2008 11:46 pm
Replies: 1
by Tudorel Lupu » Mon Jan 28, 2008 7:21 pm

1 Replies

939 Views

Last post by Radu Titiu
Mon Jan 28, 2008 11:46 pm
Matrice inversabile cu anumite proprietati

Last post by Tudorel Lupu « Mon Jan 28, 2008 7:13 pm

by Tudorel Lupu » Mon Jan 28, 2008 7:13 pm

0 Replies

949 Views

Last post by Tudorel Lupu
Mon Jan 28, 2008 7:13 pm
AB-BA comuta cu A si B, atunci A comuta cu B

Last post by Cezar Lupu « Sat Jan 26, 2008 11:12 pm
Replies: 1
by Bogdan Posa » Wed Jan 23, 2008 9:08 pm

1 Replies

880 Views

Last post by Cezar Lupu
Sat Jan 26, 2008 11:12 pm
Matrice de ordin n cu A^n=0

Last post by Bogdan Posa « Sun Dec 23, 2007 9:50 pm
Replies: 1
by Cezar Lupu » Thu Dec 20, 2007 7:15 pm

1 Replies

934 Views

Last post by Bogdan Posa
Sun Dec 23, 2007 9:50 pm
Matrice cu determinant nul

Last post by Cezar Lupu « Wed Nov 28, 2007 2:34 am
Replies: 1
by Mircea Cimpoeas » Tue Nov 27, 2007 9:05 pm

1 Replies

850 Views

Last post by Cezar Lupu
Wed Nov 28, 2007 2:34 am
Doua matrice comuta, atunci una este polinom de cealalta?

Last post by Cezar Lupu « Wed Nov 07, 2007 1:07 am

by Cezar Lupu » Wed Nov 07, 2007 1:07 am

0 Replies

695 Views

Last post by Cezar Lupu
Wed Nov 07, 2007 1:07 am
Gradul polinomului este mai mic decat rangul matricei

Last post by Alex Dura « Sat Nov 03, 2007 2:46 pm
Replies: 1
by Cezar Lupu » Thu Nov 01, 2007 3:21 pm

1 Replies

811 Views

Last post by Alex Dura
Sat Nov 03, 2007 2:46 pm

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