Happy Mathematics - Fall in Love with the Devil Subject in Your Eyes

This book starts from part of the content of current middle school mathematics textbooks and systematically introduces a series of interesting mathematical theories extended from them, including set theory, the concept of "infinity", polynomial equations and root-finding formulas, the establishment of (exponential) functions, geometric interpretation and application of trigonometric functions, mathematical foundations and paradoxes, etc. It not only spreads mathematical knowledge, but also tells the history and culture of mathematics that cannot be learned in the classroom in a relaxed and humorous language. This book is suitable for middle school students and college mathematics enthusiasts to read. It can broaden your mathematical horizons, improve your mathematical thinking and deepen your understanding of mathematics.