2, remember the intersection coordinates of a function and a coordinate axis, and be familiar with it.
3, grasp the narrative of the problem, the general principle of the general law is simultaneous equations (of course, there are intersections).
Function was actually talked about in junior high school, of course, it was the simplest primary school and middle school at that time, and the most dramatic function of the whole high school function was actually the middle school function. The general strategy of learning functions well is to master the nature of each function, so that it can be used freely and prepared. The properties of functions are monotonicity, parity, boundedness and periodicity. The only functions that can perfectly embody the above properties are sine function and cosine function in middle school trigonometric function. These are the basic properties of functions. Symmetry can be derived from parity, which is related to quadratic function. In fact, quadratic function can be associated with all the above properties, and any function can, because these properties are abstracted from a large number of basic functions, so as to describe them more vividly. I'm sure you have a deep understanding of this. The remaining power functions, exponential functions, logarithmic functions and so on are not complicated in themselves. As long as we grasp the properties, such as the definition domain of logarithmic function and the value domain of exponential function, the questioner can make a big fuss and the respondent can swim in it. Nature is the most essential thing of function, and the essence of the world is simplicity. Complexity is only an external manifestation, and function can well reflect this. In addition, you have to learn derivatives in senior three. Learning well can help you understand the things ahead, while learning badly will disturb people's thinking. Therefore, I suggest you preview, because preview will never let you fall behind. My core learning experience is preview, which makes me far ahead of other students in mathematics and invincible.
To sum up, in the process of learning the function, we should grasp its nature and preview the learning methods (if we have the ability, it is best to learn by ourselves).
. Function is the focus of the college entrance examination, that is, the proposition of the college entrance examination does contain the idea of taking function as the key link. How to learn functions well mainly depends on the following points. First, we should know the six key functions of the college entrance examination, first, the exponential function; Second, logarithmic function; Third, trigonometric functions; Quadratic function; Fifth, the least graded function; Six, double hook function y = x+a/x (a > 0). To master the properties and images of functions, use the properties and images of these functions to solve problems. In addition, there are three main methods to solve the function. The first method is the basic function method, which uses the properties of basic functions and images to solve problems. The second method is to construct an auxiliary function; The third method is function modeling. Pay special attention to the idea of functions and equations, and combine numbers with shapes. You said you didn't know how to start with the problem. In fact, there are many tools of function, such as image, monotonicity, parity, periodicity, extreme value, maximum value and derivative, which are all tools for studying function and the starting point for solving problems. Put the basic questions in these places first (that is, directly let you find monotone interval, definition domain, value domain, period, derivative).