Matrix 10 - QuestionCove
OpenStudy (eric_d):

Matrix 10

3 years ago
OpenStudy (eric_d): 3 years ago
OpenStudy (eric_d):

@mathmale

3 years ago
OpenStudy (eric_d):

10) b)

3 years ago
OpenStudy (eric_d):

@ganeshie8

3 years ago
OpenStudy (mathmale):

You want to find the inverse of matrix 10b? Have you done matrix inverses before? If so, using which method or methods?

3 years ago
OpenStudy (sidsiddhartha):

i think gauss jordan method will be helpful

3 years ago
OpenStudy (mathmale):

I think so too. Eric, what's the first thing you'd do to matrix 10b to prepare yourself to find its inverse?

3 years ago
OpenStudy (sidsiddhartha):

if A is reduced to I by elementary transformation then $PA=I$ where $P=P_nP_{n-1}...P_2P_1$ then $P=A^{-1}$

3 years ago
OpenStudy (eric_d):

Usually, I use this method http://prntscr.com/4bqi41

3 years ago
OpenStudy (eric_d):

Nw, I'm required to use elementary row of operation for this question

3 years ago
OpenStudy (mathmale):

Have you used elem. row ops on easier matrices?

3 years ago
OpenStudy (eric_d):

Nope

3 years ago
OpenStudy (eric_d):

I've never use this method before

3 years ago
OpenStudy (mathmale):

Then it'd be a big jump from where you are now to finding the inverse of a 3x3 matrix. Have you heard of the "Gauss-Jordan" method? It involves "elementary row operations"

3 years ago
OpenStudy (eric_d):

No

3 years ago
OpenStudy (mathmale):

We'll have to decide what we together should do at this point. I can teach you how to do any or all of the work involved, but we'd be starting from scratch, and the process would take quite some time. Have you a reference book that deals with the "Gauss-Jordan" method?

3 years ago
OpenStudy (eric_d):

no

3 years ago
OpenStudy (mathmale):

Learning this method would come first; finding the inverse of matrix 10b would follow. So I assure you I'm not taking you off topic. Eric, suggest you do Internet searches for pertinent info and examples when faced with a situation like this one. I performed my own Internet search for "Gauss-Jordan elimination method" and came up with quite a lot of info: https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1CHFX_enUS461US461&ion=1&espv=2&es_th=1&ie=UTF-8#q=gauss-jordan%20elimination%20method I'd suggest you focus on the first reference: www.purplemath.com/modules/systlin6.htm

3 years ago
OpenStudy (eric_d):

ok

3 years ago
OpenStudy (mathmale):

Rather than give you a lengthy explanation, I'm going to lead you thru the solution of an easy actual problem. Suppose you were given

3 years ago
OpenStudy (eric_d):

Thank you

3 years ago
OpenStudy (mathmale):

|dw:1407767777335:dw| (This is a matrix equation) ...and that you are asked to find the values of x and y that satisfy this system of linear equations. I'll go further into that too, as necessary.

3 years ago