multiplying matrices

Nov 2009
75
0
In general ABA is NOT equal to B! And A(ACA)A'= (A^2)C(AA') which is equal to (A^2)C only if AA'= I which is not always true.

thank you both for your help(Wink)
why isnt this always true? if and only if say AA' = I ... it makes sense for it to be true right??
 

dwsmith

MHF Hall of Honor
Mar 2010
3,093
582
Florida
thank you both for your help(Wink)
why isnt this always true? if and only if say AA' = I ... it makes sense for it to be true right??
If there is no inverse matrix, \(\displaystyle AA^{-1}\) doesn't exist since \(\displaystyle A^{-1}\) doesn't exist.