For the following set, state with reasons with reasons whether it is a null set.
$C = {c | c \in N, c$ is odd and $c^{2}$ is even $}$

Question

Q. For each of the following sets. state with reasons whether it is a null set.
(i) A = {x|x

\in

I x² is not positive}
(ii) B = {b|b

\in

N, 2b + 1 is even}
(iii) C = {c|c

\in

N, c is odd and c² is even}

Answer 1

Set C is an empty set or null set as the square of odd natural number is odd.
For example,

3^{2} = 9; 7^{2} = 49

For the following set, state with reasons with reasons whether it is a null set.C={c|c∈N,c is odd and c2 is even}