Proof that inverse of a matrix is unique
_If B and C are both inverses of the matrix A,then B=C_.
Can't i prove it in following way ?
Proof:
`AB=BA=I` and `AC=CA=I`,then `BA=CA=I`
By postmultiplication $\Rightarrow (BA)(A^{-1})=(CA)(A^{-1})=(I)(A^{-1})\Rightarrow B=C=A^{-1}$,
or by premultiplication $AB=AC=I\Rightarrow (A^{-1})(AB)=(A^{-1})(AC)=(A^{-1})(I)\Rightarrow B=C=A^{-1}$.