Which of the following relations represent a function? {(-1,-3),(3,2),(3,7)}
{(-1,4),(2,7),(3,7)}
{(-3,7),(3,-7),(3,7)}
{(-1,4),(-1,7),(3,5)}

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?