Analysis of teaching tasks:

Last class, I have learned the knowledge of monotonicity of trigonometric functions, including monotonicity of sine and cosine and their corresponding intervals. The method is to use image and combine periodicity. The application of monotonicity of functions is mainly reflected in two aspects:

① comparison size

② Find the monotonous interval.

Of course, monotonicity is closely related to other properties of functions, such as parity and periodicity. Considering the study of new knowledge, these exercises are not selected for the time being.

Reflection after teaching:

① As the teaching is conducted in the form of problem groups, from the point of classroom feedback, the completion of substantive goals is ideal, and the classroom atmosphere is full of "warmth".

Of course, although the textbooks are all handled according to their own understanding, there are still many students in ordinary classes who lack sufficient understanding of the idea of variables, and their understanding of the essence of trigonometric functions is superficial. The lack of abstract thinking has increasingly restricted the in-depth study and improvement of mathematics. For example, some students think that the maximum value of y=sin2x can be 2. What is the refraction behind the wrong answer? Mainly lies in the strangeness and misunderstanding of the definition and symbols of trigonometric functions. But apart from students' lack of abstract thinking, teachers themselves did not attach importance to the breakthrough in this link.