e206k - MAS 3105 May 18, 2006 Quiz II and Key Prof. S....

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: MAS 3105 May 18, 2006 Quiz II and Key Prof. S. Hudson Suppose you are asked to find the inverse of a 2x2 matrix A , which appears below. And I do most of the calculation for you: [ A | I ] = 1 1 1- 2- 1 1 → 1 1 1 1 2 1 → 1- 1 ? 1 2 1 1) A is the first two columns of the first matrix. What is A- 1 ? Check your answer. 2) The first “ → ” is a G.E. step. Find the elementary matrix E 1 that does that step. Then find E- 1 1 . 3) Express A- 1 as a product of elementary matrices. (Write them out, in order). 4) You can use this calculation to get an LU factorization of A . What is L ? [hint: use part 2] What is U ? Check that A = LU . 5) [20 pts) Choose ONE of these to prove, on the back. Use words and sentences and standard methods to completely explain your reasoning and your formulas. a) If A and B are symmetric and AB = BA , then AB is symmetric. b) If A is nonsingular then det(A) is nonzero....
View Full Document

This note was uploaded on 12/26/2011 for the course MAS 3105 taught by Professor Julianedwards during the Spring '09 term at FIU.

Page1 / 2

e206k - MAS 3105 May 18, 2006 Quiz II and Key Prof. S....

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online