Question

What should be checked to determine whether a relation is symmetric?

Options

• Whether every \((a,a)\) is present

• Whether every \((a,b)\) has the reverse pair \((b,a)\)

• Whether all pairs in \(A\times A\) are present

• Whether no element is related to any element

Answer 1

Symmetry is checked by reversing each ordered pair. If \((a,b)\) occurs, \((b,a)\) must also occur for the relation to be symmetric.