Exercise 2.3.7

Answers

To reverse $E_{31}$ , add 7 times row 1 to row 3 . The inverse of the elimination matrix

E = [\begin{matrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ - 7 & 0 & 1 \end{matrix}] is E^{- 1} = [\begin{matrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 7 & 0 & 1 \end{matrix}]

Multiplication confirms $E E^{- 1} = I$ .

mathchakra

2021-11-20 15:14