Hey guys,

I just want to know when an inverse or transpose of something ( vector or matrix ) will multiply a (vector or matrix) from the right or left to make it into an I.

For example,

A^TAx = b

A^-1A = I

S^-1AS

I'm having trouble when the rule applies to make something into an Identity when multiplying by an inverse or transpose.

Does it have to be square? linearly independent? singular? non singular? etc.