Let R and S be the given relations from A to B Compute R U S

Let R and S be the given relations from A to B. Compute R U S.
A={a,b,c}; B= {1,2,3}
R= {(a,1), (b,1), (c,2), (c,3)}
S= {(a,1), (a,2), (b,1), (b,2)}

Solution

{(a,1), (a,2), (b,1), (b,2), (c,2), (c,3)} is the answer.

R U S means all elements in the set R and S. The elements common in both R and S should be included only once while writing R U S.