f(V) = (sqrt(3)/2, 1]
f(V)c = {x in [-1, 1] | x not in f(V)}.
sqrt(3)/2 is not in f(V), so it IS in f(V)c. Thus, [-1, sqrt(3)/2].
If that were the complement, then f(V) union f(V)c would not be the entire interval... which is a basic complement law. right?
Call U the universe of discourse...