mammothrob
Junior Member
- Joined
- Nov 12, 2005
- Messages
- 91
This proof is looking kinda weird to me. Does this look correct?
Let (A) be a nonsingular invertable matrice.
(I) is the identity matrix
If A(A)=A, the prove that A=I
\(\displaystyle \begin{array}{l}
A^2 = A \\
AA = A \\
A^{ - 1} (AA) = A^{ - 1} A \\
(A^{ - 1} A)A = A^{ - 1} A \\
IA = I \\
A = I \\
\end{array}\)
Let (A) be a nonsingular invertable matrice.
(I) is the identity matrix
If A(A)=A, the prove that A=I
\(\displaystyle \begin{array}{l}
A^2 = A \\
AA = A \\
A^{ - 1} (AA) = A^{ - 1} A \\
(A^{ - 1} A)A = A^{ - 1} A \\
IA = I \\
A = I \\
\end{array}\)