Let A={1,2,3,4} and let R, S, T, and U be the following relations: R={(1,1),(1,2),(1,3),(1,4)} S={(1,1),(2,1),(3,1),(4,1)} T={(1,2),(3,4),(4,1)} U={(2,1),(4,4),(3,1),(2,3)} For each of R, S, T, and U determine whether they are reflexive, symmetric or transitive and determine whether the given relations in A is an equivalence relation or not.