15. The square matrix A is invertible if there is
a matrix B such that AB = BA =I , where I
is the identity matrix. The matrix B is called
the inverse of A and is denoted by A-1
Inverse Matrix
22. Suppose there are two sets one is A & the
other one is B.
Union of A and B
Intersection of A and B
A B
A B
A B
23. De- Morgan’s Law
1. Complement of a union is the
intersection of complements.
(AUB) =A B
2. Complement of an intersection is the union of
complements.
(A B) =AUB