Instruct: Classify an Amazon review into positive or negative sentiment.
Query: The most confusing calculus book I have ever purchased

This book is confusing in two ways: First, it launches into complex concepts, equations, problems and solutions without ever explaining the underlying fundamentals; the authors assume that the reader is already in command of many concepts and terms that would almost certainly escape a person who is "Utterly Confused" by calculus. Second, although the content of the book would be useful to a person who had successfully completed a formal education in calculus and was in need of a review, the authors chose to bill this book as a quick and easy way to understand the intricacies of calculus for those who have failed to grasp the basic fundamentals. They do a great disservice to the readers whom they dupe into buying this book by making false claims about its nature.