Question

5. Let \( S \) be the set of all straight lines in a plane. Let \( R \) be a relation on defined by \( a R b \Leftrightarrow a \| b \). Then, \( R \) is (a) reflexive and symmetric but not transitive (b) reflexive and transitive but not symmetric (c) symmetric and transitive but not reflexive (d) an equivalence relation

Answer 1

c ) Symmetric & transitive but not reflexive

as   if the line is a//a then it becomes concurrent