Your Turn 12. Let f:R→R,f(x)=x 2
. (a) Let T be the closed interval [50,300]. Is −8∈f −1
[T] ? Which interpretation of f −1
[T] (collection or test condition) are you using? (b) If T={5,4,0,−1}, compute f −1
[T]. Which interpretation of f −1
[T] (collection or test condition) are you using? (c) If T is the closed interval [4,9], compute f −1
[T]. (Start with the description {a∈A:f(a)∈T} and insert the appropriate specifics of A,f, and T. You will obtain an inequality that you will have to solve.)