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Let R be the relation over the set of all straight lines in a plane such that `l_(1) R l_(2) iff l_(1) _|_ l_(2)`. Then, R isA. symmetricB. reflexiveC. transitiveD. an equivalence relation |
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Answer» Correct Answer - A Clearly, R is not a reflexive relation, because a line cannot be perpendicular to itself. Let `l_(1) R l_(2)`. Then, `l_(1) R l_(2)implies l_(1) _|_ l_(2) implies l_(2)_|_l_(1)implies l_(2)Rl_(1)` `therefore` R is a symmetric relation. R is not a transitive relation, because if `l_(1) _|_ l_(2) and l_(2) _|_l_(3)`, then `l_(1)` may be parallel to `l_(3)`. Hence, option (a) is correct. |
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