Question

Question #26c2d

Answer 1

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. #