理解对数函数的概念和意义,掌握对数函数定义域、值域的求法,能画出具体对数函数图像,并能根据对数函数的图像说明对数函数的性质,掌握对数函数的单调性,会进行同底对数和不同底对数大小的比较。通过指数函数、对数函数的学习,加深理解分类讨论、数形结合这两种重要数学思想的意义和作用。 Understand the concept and significance of logarithmic function, grasp the domain of logarithm function, find the range of value, draw the image of specific logarithm function, explain the nature of logarithmic function according to the logarithm function image, master the logarithm function Monotonic, will be the same end of the logarithm and different base logarithmic size of the comparison. Through the exponential function, the logarithm function of learning, to deepen the understanding of the classification discussion, the combination of these two important mathematical ideas significance and role.