Question
Let $$N$$ be the set of non-negative integers, $$I$$ the set of integers, $${N_p}$$ the set of non-positive integers, $$E$$ the set of even integers and $$P$$ the set of prime numbers. Then :
A.
$$I - N = {N_p}$$
B.
$$N \cap {N_p} = \phi $$
C.
$$E \cap P = \phi $$
D.
$$N\Delta {N_p} = I - \left\{ 0 \right\}$$
Answer :
$$N\Delta {N_p} = I - \left\{ 0 \right\}$$
Solution :
$$\eqalign{
& N\Delta {N_p} = \left( {N - {N_p}} \right) \cup \left( {{N_p} - N} \right) \cr
& = \left\{ {1,\,2,.....} \right\} \cup \left\{ {.....,\, - 2,\, - 1} \right\} \cr
& = I - \left\{ 0 \right\} \cr} $$