Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202331 JanuaryEvening Shift
Exam
JEE Main
Year
2023
Date
31 January
Shift
Evening Shift
Subject
Mathematics
Chapter
Sets and Relations

JEE Main 2023 · 31 January · Evening Shift · Mathematics · Sets and Relations

Among the relations S = \ (a, b): a, b ∈ R - \ 0\ , 2 + (a)/(b) >...

Among the relations
S={(a,b):a,b∈R−{0},2+ab>0}S = \left\{\left(a, b\right): a, b \in R - \left\{0\right\}, 2 + \dfrac{a}{b} > 0\right\} and T={(a,b):a,b∈R,a2−b2∈Z}T = \left\{\left(a, b\right): a, b \in R, {a}^{2} - {b}^{2} \in Z\right\},

Options

  1. ASS is transitive but TT is not
  2. Bboth SS and TT are symmetric
  3. Cneither SS not TT is transitive
  4. DTT is symmetric but SS is not

Correct answer

D. TT is symmetric but SS is not

Step-by-step solution

Given,

a,b∈Ia, b \in I and relation TT is defined as a2−b2∈I{a}^{2} - {b}^{2} \in I

Now if a2−b2∈I{a}^{2} - {b}^{2} \in I so b2−a2{b}^{2} - {a}^{2} will also be integer, for example if 52−42=9{5}^{2} - {4}^{2} = 9 is integer then 42−52=−9{4}^{2} - {5}^{2} = - 9 is also a integer,

Now checking transitive,

If 42−32=7{4}^{2} - {3}^{2} = 7 is an integer, 32−22=5{3}^{2} - {2}^{2} = 5 is an integer then 42−22=12{4}^{2} - {2}^{2} = 12 is also an integer, hence we can say that TT is symmetric and transitive,

Now checking relation SS which is defined as 2+ab>02 + \dfrac{a}{b} > 0,

So, if we replace ab\dfrac{a}{b} by −19\dfrac{- 1}{9} then 2+ab>02 + \dfrac{a}{b} > 0 is true but we take ba=−9\dfrac{b}{a} = - 9 for symmetric we get 2+ba=2−9=−7≯02 + \dfrac{b}{a} = 2 - 9 = - 7 ≯ 0 hence, the relation is not symmetric,

Now checking transitive, now if 2+ab>0⇒ab>−22 + \dfrac{a}{b} > 0 ⇒ \dfrac{a}{b} > - 2 and bc>−2\dfrac{b}{c} > - 2 then we cannot say that ac>−2\dfrac{a}{c} > - 2,

For example if we take 41>−2,1−1>−2\dfrac{4}{1} > - 2, \dfrac{1}{- 1} > - 2 then 4−1≯−2\dfrac{4}{- 1} ≯ - 2, hence it is not transitive,

Hence, we can say that TT is symmetric and SS is not.

Practice Sets and Relations on Quantrex Academy →

More from Sets and Relations

Let S = \ 1, 2, 3, …, 10\ . Consider the set X = \ R : R is an equivalence relation on… JEE Advanced 2026Consider the relation R on the set \ -2,-1,0,1,2\ defined by (a, b) ∈ R if and only if… JEE Main 2026Let R = \ (x, y) ∈ ℕ × ℕ : _e(x + y) ≤ 2\ . Then the minimum number of elements, required… JEE Main 2026Let A = \ 1, 4, 7\ and B = \ 2, 3, 8\ . Then the number of elements, in the relation R =… JEE Main 2026Let A = \ 2, 3, 4, 5, 6\ . Let R be a relation on the set A × A given by (x, y) R (z, w)… JEE Main 2026Let R be a relation defined on the set \ 1,2,3,4\ ×\ 1,2,3,4\ by R=\ ((a, b),(c, d)): 2… JEE Main 2026Let A=\ 0,1,2, …, 9\ . Let R be a relation on A defined by (x, y) ∈ R if and only if… JEE Main 2026Let A=\ -2,-1,0,1,2,3,4\ . Let R be a relation on A defined by x Ry if and only if 2 x+y… JEE Main 2026The number of elements in the relation R=\ (x, y): 4 x^ 2 +y^ 2 <52, x, y ∈ Z\ is JEE Main 2026Let S be the set of the first 11 natural numbers. Then the number of elements in A=\ B ⊆… JEE Main 2026Let the relation R on the set M=\ 1,2,3, …, 16\ be given by R=\ (x, y): 4 y=5 x-3, x, y ∈… JEE Main 2026Let A=\ x:|x^ 2 -10| ≤ 6\ and B=\ x:|x-2|>1\ . Then JEE Main 2026Let A=\ 2,3,5,7,9\ . Let R be the relation on A defined by x R y if and only if 2 x ≤ 3 y… JEE Main 2026The number of relations, defined on the set \ a, b, c, d\ , which are both reflexive and… JEE Main 2026Let the set of all relations R on the set \ a, b, c, d, e, f\ , such that R is reflexive… JEE Advanced 2025Let A=\ 0,1,2,3,4,5\ . Let R be a relation on A defined by (x, y) ∈ R if and only if max… JEE Main 2025 Full Sets and Relations list Sets and Relations JEE Maths PYQsJEE Mathematics PYQs All JEE Main PYQs