函数知识作为高中数学的主线,贯穿于整个高中数学学习中。函数的定义域是构成函数的两大要素之一,函数的定义域,似乎是非常简单的,然而在解决问题中不加注意,常常会使人误入歧途。在解函数题中强调定义域对解题结论的作用与影响,对提高学生的思维能力是 Function knowledge as the main line of high school mathematics, throughout the high school mathematics learning. The domain of a function is one of the two major elements that make up a function. The domain of a function seems to be very simple. However, paying attention to the problem is often misleading. In the function of solving problems, it emphasizes the role and influence of domain definition on the solution of the problem,