Question #26c2d

1 Answer
Sep 27, 2016

Answer:

See the Explanation>

Explanation:

Ans. to Q(1) : To verify whether a set #A# is a subset of another

set #B#, we have to check that, each & every element of the set

#A# is also an element of the set #B#.

Here, the set #A# has two elements, namely, #1 & 2#, and we see

that they are also the elements of the set B.

Accordingly, #A sub B#.

Ans. to Q(2) :

The complement of #B# (in #NN#), denoted by #B'# is the set of

all those elements in NN which are not in #B#.

Hence, #B'={3,4,5,... ... ... ...}#.

We may write, #B'=NN-{1,2}#.

Ans. to Q(3) :

Indeed, #A=B iff A sub B,and, B sub A#.

In fact, this is the Defn. of Equality of Sets. #