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# Matrices Q FP1 Watch

1. A-1C-1 = (CA)-1

2. (Original post by tsr13579)
A-1C-1 = (CA)-1

Let

Front multiply by A.

Front multiply by C.
3. let X = A-1C-1

Front multiply by A: AX = A-1AC-1 = IC = C
Front multiply by C: CAX = CC-1 = I

I've ended up with CAX=I, where do I go from here?
4. (Original post by tsr13579)
let X = A-1C-1

Front multiply by A: AX = A-1AC-1 = IC = C
Front multiply by C: CAX = CC-1 = I

I've ended up with CAX=I, where do I go from here?
If you let

Then

As

5. (Original post by tsr13579)
let X = A-1C-1

Front multiply by A: AX = A-1AC-1 = IC = C
Front multiply by C: CAX = CC-1 = I

I've ended up with CAX=I, where do I go from here?
Slightly worried by this!

You should know that so

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Updated: January 11, 2015
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