Which of the following shows the expression written with a single radical? a) 3*2^(1/2); b) 3*2^(1/4); c) 6*2^(1/2); d) 6*2^(1/4)? The book says that the answer is d), but I do not understand why. They all look like single radicals to me!

I think I would toss the book, as at least in this instance, it has little educational value.