Notes-Chapter 4-Part 3

# Notes-Chapter 4-Part 3 - LINEAR MODELS AND MATRIX ALGEBRA...

This preview shows pages 1–6. Sign up to view the full content.

LINEAR MODELS AND MATRIX ALGEBRA - Part 3 Chapter 4 Alpha Chiang, Fundamental Methods of Mathematical Economics 3 rd edition

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

View Full Document
Identity Matrix 2 3 1 0 0 1 0 0 1 0 0 1 0 0 1 I I = = Characteristics: It is like the number 1: a(1) = (1)a=a IA = AI = A
Identity Matrix Special Nature of I Matrices : it is possible to insert or delete an I w/o affecting the matrix product. 2 ( ) Interesting case: if: ( ) ( ) mxn nxn nxp n n n n k n n A I B AI B AB A I AI I I I I = = = = = =

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

View Full Document
Inverses and their Properties: For a given matrix A, The transpose is always derivable. Its inverse matrix (another type of derived matrix) may or may not exist. The inverse of matrix A is denoted by A -1 is defined only if A is a square matrix.
1 1 1 1 1 1 1 1 1 1 1 ( ) ( ) ( ') ( )' AA A A I A A AB B A A A AA A A I - - - - - - - - - - - = = = = = = = Whether A is pre-multiplied or postmultiplied by A -1 , the product will be the same identity

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 11/09/2011 for the course ECON 101 taught by Professor Richards during the Spring '11 term at Cambrian College.

### Page1 / 9

Notes-Chapter 4-Part 3 - LINEAR MODELS AND MATRIX ALGEBRA...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online