Trigonometric function includes the definition, image and properties of trigonometric function; The relationship and inductive formulas of trigonometric functions with the same angle: the sum-difference multiple half-angle formula and the product sum-difference, sum-difference product formula (no need to remember). The focus is on the image of trigonometric function, the properties of trigonometric function and the identity deformation of trigonometric function. The principle of college entrance examination proposition is to focus on key contents, so the proposition always focuses on these key issues. Judging from the national college entrance examination questions in recent years, there are two or three multiple-choice questions or fill-in-the-blank questions about trigonometric function content every year, which are often put forward at the intersection of trigonometric function knowledge and trigonometric function knowledge network, with the sum and difference of two angles. Because the content of half-angle formula, sum-difference product, product and difference is deleted from the new curriculum, the investigation of triangle part focuses on the image and properties of trigonometric function, which is usually transformed into angular function formula by constant deformation first, and then its property relationship is studied. The questions involving trigonometric functions account for about 12% of the total score of the whole paper. The college entrance examination pays attention to the basic knowledge of function. Generally speaking, the test questions are not difficult.

Although trigonometric function knowledge is not the key content of high school mathematics, it is very important in algebra and is a compulsory content of college entrance examination. The test questions will still focus on the properties and image propositions of trigonometric functions as before. Through the statistics and analysis of the previous college entrance examination, we found the problems of transformation and symmetry of trigonometric function images. It is known that trigonometric function images and their analytical expressions are the points that candidates lose points, and it is estimated that there will be such problems. Through the research, it is also concluded that the form of trigonometric function test questions will still be multiple-choice questions and fill-in-the-blank questions in the future. The difficulty will not be great, but it will be controlled at the level of "easy" to "medium". In addition, it should be noted that the difficulty of multiple-choice questions and fill-in-the-blank questions is rising, the test questions may become more and more flexible, and the requirements for thinking are getting higher and higher.

As the new curriculum plan is about to be implemented nationwide, the examination of trigonometric function identity deformation will be weakened. Another noteworthy phenomenon is that in recent years, if there are plural questions, there will be no triangular questions, and if there are triangular questions, there will be no plural questions. The plural questions must take into account the examination of triangles.

In recent years, trigonometric function images are mostly related to trigonometric function test questions. In the research, analysis and statistics of trigonometric function test papers, it is found that the requirements for thinking are getting higher and higher. The inequality of function, the maximum value of trigonometric function, symmetry problem and periodicity problem are all related to the image of trigonometric function. Therefore, when learning the knowledge of trigonometric function, we must first master the image of trigonometric function, with emphasis on the image of function y=Asin(ωx+φ), which requires us to master the "five-point method" drawing skillfully.

In the constant deformation of trigonometric functions, we should pay attention to the transformation of angles and the exchange of functions. In the usual practice, we should pay attention to the constantly changing practice, and pay attention to the purpose and rationality of calculus in the operation.

One of the characteristics of the present proposition is to increase the amount of thinking and reduce the amount of calculation. Therefore, when answering multiple-choice questions, we should pay attention to the skills and methods of solving problems. In addition, the position of triangle in high school mathematics is not too high in the exam instructions.

Through the research on the proportion of trigonometric function in college entrance examination, we can understand and understand the proposition principle, direction and focus of trigonometric function in college entrance examination. Clear this direction, understand where to strengthen training, and firmly grasp it, so as not to lose too many points in the exam and suffer big losses.

Learning this knowledge can not only reduce the academic burden, but also have more time to learn other knowledge, thus improving their own quality in an all-round way.