Nicolas Mrowietz

01:28

yes

Marc Foertig

01:28

Yes

Michelle

01:30

yes

Petz

02:13

like last time please

Nicolas Mrowietz

02:15

start with Sheet 11

Albina Kudoyarova

02:15

sheet 11, please

Michelle

02:16

sheet 11 :)

yael

02:17

Sheet 11

Tesii

02:18

I would like to start with sheet 11

nikolaihorozov

06:22

yes

Tesii

06:23

no...

Tesii

10:55

thanks!

Nicolas Mrowietz

17:09

So if Q(x) is equal to Zero is it Semi-positive-definite or Semi-negative-definite? Because 0 is included in both definitions...

Nicolas Mrowietz

18:58

ah okay, thanks!

Tesii

20:30

yes

nikolaihorozov

20:30

i think so

nikolaihorozov

20:41

yes

Sari Issa

20:44

So if Q sends all vectors in R^n to 0, q is both negative and positive semidefinite?

Sari Issa

21:34

Ok great

Alessio D'Andrea

23:09

false

Nicolas Mrowietz

23:11

false?

Sophia

23:16

can also be semi-

Alessio D'Andrea

23:18

It could also be semi

Tesii

26:54

no..

Tesii

29:20

yes

Tesii

29:26

thanks!

Sari Issa

31:22

Isnt a x^2 term missing?

Tesii

31:40

ahaa yes now it's clear

Tesii

31:46

thanks for the example

Aline Klaus

35:25

does this work for all symmetric matrices?

nikolaihorozov

41:17

yes

Tesii

41:20

yes

Aline Klaus

44:25

in the opposite, if i know the Eigenvalues, i can directly say the quadratic form is pos/neg/… definite? (even if i dont know the quadr. form yet)

Aline Klaus

44:41

okay thanks

nikolaihorozov

50:53

can we use eigenvalues or determinants to see whether a matrix is semi positive or negative

nikolaihorozov

51:41

ok thank you

Sari Issa

54:39

A question to the matrix S, if one of the eigenspaces has a dimension>1, do we always simply use the basis of the eigenspace rather than the eigenvector?

Sari Issa

55:12

can we use any eigenvectors in the space?

Sari Issa

55:22

in S

Sari Issa

55:57

ok thanks

Marc Foertig

56:28

Thanks very much as always :)

Nicolas Mrowietz

56:29

thanks!

Michelle

56:29

Thank you

Aline Klaus

56:32

merci

nikolaihorozov

56:32

thank you very much

Albina Kudoyarova

56:34

thanks a lot!

Alessio D'Andrea

56:39

Thanks!

rosie

56:43

you explain so good! thank you

Robert Bibaj

56:53

how many sheets are left? 2 or 3?

Tesii

57:02

thanks for your help!

j

57:10

thank you!!

Robert Bibaj

57:14

thx