Question

Help needed

Answer 1

@freckles

Answer 2

@Directrix

Answer 3

what does it mean for a matrix to be singular?

Answer 4

and for that matter, what does A and B have to do with B^* being singular?

Answer 5

a matrix is singular iff its determinant =0

Answer 6

and im not sure

Answer 7

it was 2 parts of the question part A was to find AB
part A was this part

Answer 8

right, so we need the determinant of the 3x3 to be 0 ... how far have you gotten?

Answer 9

.... by working the determinant process id imagine.

of course, for a 3x3 i do the shortcut process similar to a 2x2

Answer 10

ok

Answer 11

i only know to do the 2x2 so far

Answer 12

the shortcut on a 3x3 is to copy the first 2 columns onto the end, and multiply the diagonals

Answer 13

write down the values of ab and c ... where do abc come from?

Answer 14

idk that what the question ask

Answer 15

you say this question is part of another one?

Answer 16

thats the whole question

Answer 17

and you sure that when you drew it up ... you made the correct entries? with pq and r?

Answer 18

yep thats exactly whats there

Answer 19

well im out of ideas on how to make this sensible then lol.

Answer 20

i can make an equation of a plane with pqr as variables ... but ive got no idea how that helps in finding some rather ambiguous abc values.

Answer 21

@amistre64

Answer 22

@amistre64

Answer 23

have you worked the determinant?

Answer 24

6(8c-8b)+2a(32)

Answer 25

and when we set that equal to 0 we get an infinite number of solutions .... all the points in a plane.

are they wanting the solution set, or something more concrete?

Answer 26

(a,b,c) = (3,3,-1) is a solution, since that makes the last column the same as the first

(a,b,c) = (0,2,2) is a solution, since that makes the last column the same as the second

and any linear combination of the first 2 columns would be a solution as well

Answer 27

6x +0y = 2a
6x+4y = 2b
-2x+4y = 2c

Answer 28

o ok

Answer 29

can it = to 0,0,0 also?

Answer 30

yes it can :) let x=0 and y=0

Answer 31

ok thanks

Answer 32

youre welcome