If 
is such that A � = I, then
Given A = 
Calculating A2:
A2 = A.A
=
=
=
=
And given that A2 = I
Then 
Comparing corresponding elements we get,
14
If is such that A � = I, then
Given A =
Calculating A2:
A2 = A.A
=
=
=
=
And given that A2 = I
Then
Comparing corresponding elements we get,