Please help ASAP: solve the following

Write a function that matches the description. a cosine function has a maximum of 5 and a minimum value of -5. f (r) =

Which choice represents the sample space ,s for this event

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?