Question

What is De morgan's law?

Answer 1

De Morgan's Law:
The complement of the union of two sets is the intersection of their complements and the complement of the intersection of two sets is the union of their complements.
To state it simply for two sets A and B,
$(A\cup B{)}^{\prime }=A^{\prime }\cap B^{\prime }$
$(A\cap B{)}^{\prime }=A^{\prime }\cup B^{\prime }$
For union of two sets, we want the elements that are in set A, Set B or common to both.
For intersection of two sets, we only want the elements that are common to both.
Diagramatically, we can also represent the law as -