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charles1118
Regular poster

Post Number: 37
 Posted on Sunday, 20 January, 2013 - 04:17 pm:

I find this difficult for my homework. Can i ask for extra help?
Emma McCaughan
Moderator

Post Number: 4848
 Posted on Sunday, 20 January, 2013 - 05:06 pm:

Whether you are allowed, I don't know - that depends on the rules of your institution. (It's probably okay unless the homework counts towards formal assessment. And our team will give you hints to help you solve it yourself, rather than doing it for you.)

For (a), you've been asked to verify, rather than derive. What would be a good way to check whether those inverse matrices are correct?
charles1118
Regular poster

Post Number: 38
 Posted on Monday, 21 January, 2013 - 03:29 pm:

This is a normal homework towards formal assessment. Thanks for you help.
For the verification, you mean by subsitution??
Thanks˜˜˜
Arun Iyer
Veteran poster

Post Number: 1300
 Posted on Monday, 21 January, 2013 - 05:02 pm:

If somebody gives you a matrix B and claims that it is inverse of A, what is way to verify that B truly is the inverse of A?
charles1118
Regular poster

Post Number: 39
 Posted on Tuesday, 22 January, 2013 - 03:09 pm:

A A(-1) =I ???? as A(-1) is unique???

sorry i am no good in maths...
charles1118
Regular poster

Post Number: 40
 Posted on Tuesday, 22 January, 2013 - 03:36 pm:

A X A(-1) = I

use this theorem to verify???
Arun Iyer
Veteran poster

Post Number: 1301
 Posted on Wednesday, 23 January, 2013 - 12:35 am:

Right.
charles1118
Regular poster

Post Number: 41
 Posted on Sunday, 27 January, 2013 - 04:39 am:

Thanks all. I have solved it˜˜˜˜˜