Besides reviewing key concepts covered in textbooks, this book covers a lot of “general rules,” which are some observations and conclusions that help solve commonly seen problems. Instead of memorizing the general rules, we strongly encourage you to understand the intuition behind the rules. Ultimately, you develop problem-solving skills when you encounter problems you are not familiar with.
Following the principle of focusing on what you do not know, most of the problems we include in this book are not textbook problems. Instead, they often require a deep understanding of the underlying concepts and may require creative ways of using the concepts. Do not get frustrated if you cannot answer some problems—or even a significant percentage of the problems—initially. Give each problem your best effort.
We highly recommend that you review the solutions even if you get all the answers right, as they may approach the same problem from a different perspective. In most cases, there is more than one way to solve a problem and some solutions may be simpler than others. A slower method may provide insights from a unique perspective, and those insights may offer a faster solution for a similar problem. Instead of coming up with an answer to a particular problem, the goal is to gradually develop problem-solving skills to solve all similar problems.