UGC NET CSE | July 2018 | Part 2 | Question: 86

Question

If $A_i = \{-i, \dots , -2, -1, 0, 1, 2, \dots , i \}$ then $\cup_{i=1}^\infty A_i$ is

• A. Z
• B. Q
• C. R
• D. C

Answer 1

Here 1 is the right ans Q,R,C are set of rational , real and complex numbers respectively

Z  is the set of integers, ie. positive, negative or zero

 Q is the set of rational numbers, ie. represented by a fraction a/b with a belonging to Z and b belonging to Z *

R is the set of real numbers, ie. all numbers that can actually exist, it contains in addition to rational numbers, non-rational numbers or   irrational

C  is the set of complex numbers, ie. the set of real numbers R and all imaginary numbers I.

Answer 2

Option A
Set of Integers  i.e. Z 

Answer 3

A (All Ineteger)

Answer 4

Option (A) - as this is the union of all Integers from -$\infty$ to +$\infty$