Among the relations
S={(a,b):a,b∈R-{0},2+ab>0} and
T={(a,b):a,b∈R,a2-b2∈Z} [2023]
(4)
For relation T=a2-b2∈I
Then, (b,a) on relation R⇒b2-a2∈I
∴T is symmetric, S={(a,b):a,b∈R-{0}, 2+ab>0}
2+ab>0⇒ab>-2⇒ba>-12
If (b,a)∈S, then 2+ba is not necessarily positive.
∴ S is not symmetric.