Thread: Matrices Question - Check i havent gone insane

1. Matrices Question - Check i havent gone insane

Ok so on this weeks home work there is the following question

Let A =
2 1
1 2

Let B =
1 1
1 -1

Part 1 says compute $B^{-1}$ which i found to be

$B^{-1}$=

0.5 0.5
0.5 -0.5

The next part is the problem it asks to show that $B^{-1}AB$is a diagonal matrix

Having multiplied $B^{-1}AB$ i dont get i diagonal matrix i get

2 1
1 2

I have checked and re-checked all my working and cant see where im going wrong?

Any help most appreciated

2. B^-1 * a =

1.5 1.5
.5 -.5

(b^-1*a)b =

3 0

0 1

Don't know why capital letters are being converted to small letters