Question

The 3×3 matrix A is transformed into I by the following elementary row operations

replace row 1 with row 1 + (4) row 3
exchange row 2 and row 3
replace row 2 with (3) row 2
exchange row 1 and row 2
exchange row 1 and row 3


a) Find the corresponding elementary matrices E1,…,E5 so that E5E4E3E2E1A=I.

b) Find A.

Answer 1

E1 have as \[\left[\begin{matrix}1 & 0 & 4 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{matrix}\right]\]

Answer 2

for E2 I got \[\left[\begin{matrix}1 & 0 & 4 \\ 0 & 0 & 1\\ 0 & 1 & 0 \end{matrix}\right]\] but they say it is wrong

Answer 3

so do you know the write answer

Answer 4

No I only know when I get it wrong

Answer 5

okay why don't you ask the pony

Answer 6

hmmm you need an identity matrix

Answer 7

i mean the UsukiDoll

Answer 8

E5E4E3E2E1A=I.

what is your original matrix?

Answer 9

last two you're swapping... rows.. but err this would be easier if you could supply the original matrix

Answer 10

awww it's offline what's the point?!

Answer 11

sicne we have transformations performed, we can construct the original matrix A

Answer 12

try this for E1 :

\(\left[\begin{matrix}0 & 13 & 0 \\ 1 & 0 & 0 \\ 0 & 3 & 0\end{matrix}\right]\)

Answer 13

try this for E2 :

\(\left[\begin{matrix}0 & 1 & 0 \\ 1 & 0 & 0 \\ 0 & 3 & 0\end{matrix}\right]\)