>> A=[2 1 1;1 2 1;1 1 2]
A =
2 1 1
1 2 1
1 1 2
>> inv(A)
ans =
3/4 -1/4 -1/4
-1/4 3/4 -1/4
-1/4 -1/4 3/4
>> A^-1
ans =
3/4 -1/4 -1/4
-1/4 3/4 -1/4
-1/4 -1/4 3/4
>>