This fantastic textbook was written by two internationally famous authors, Fomenko and Kunii. Because this book requires only high school mathematics, students of the 1st year of undergraduate course can start reading it smoothly. They can learn all the necessary mathematics for visualization through this book. This book covers not only linear but also non-linear problems with a lot of examples. Even students in cognitive science or financial analysis who should solve non-linear problems will find this book helpful.