4. let (un), (un) be two real sequences with lim un =l, lim vn = m. if z, = max{un, un}, yn = min{un, vn}, prove that the sequence (tn) con- verges to max{l, m}

4. Let (un), (Un) be two real sequences with lim un =l, lim vn = m. If z, = max{un, Un}, yn = min{un, Vn}, prove that the sequence (Tn) con- verges to max{l, m} and the sequence (yn) converges to min{l, m Hint. max{a, b}= la +b+ | a - b I}, min{a, b}= {a +b-I a - b I for all a,bE R.J