Past exam of the year 1 of the computer science course of the University of Oxford / 2017 / Digital systems, linear algebra, introduction to formal proof / 5 / c / i

Table of contents
- Solution i

Solution

First subtract row one from row two, using

E_{1}

; then subtract four times the updated row two from row three, using

E_{2}

:

E_{1} = 1 - 1 0 010001, E_{2} = 100 01 - 4 001 .

The updated second row is

(0, 1, 2)

and the final third row is

(0, 0, - 4)

. Hence

E_{2} E_{1} A = U

and

L = E_{1}^{- 1} E_{2}^{- 1}

. The resulting LU decomposition is

L = 110014001, U = 100110 12 - 4, A = LU .

Reversing the order when undoing the elementary operations is essential.

 Ancestors (12)

 View article source

 Discussion (0) New discussion

There are no discussions about this article yet.

 Articles by others on the same topic (0)

There are currently no matching articles.

  See all articles in the same topic Create my own version