I. teaching material analysis

The cosine formula of the difference between two angles is a compulsory course of senior high school mathematics in version A, which is the People's Education Edition. Chapter 3, Triangle Identity Transformation, Section 1, Section 2

Sine, cosine and tangent formulas of angle sum and difference. This section mainly gives the cosine formula of the difference between two angles.

Deduction should guide students to participate actively, think independently and draw corresponding conclusions by themselves.

Second, the teaching objectives

1, guide students to establish the cosine formula of the difference between two angles. Through the simple application of the formula, students can initially understand the structure and function of the formula and lay a good foundation for establishing other sum-difference formulas.

2. Through the design of the subject background, students' awareness of application is enhanced and their enthusiasm for learning is stimulated.

3. In the process of exploring formulas, gradually cultivate students' ability to analyze and solve problems, and cultivate students' learning ability.

Ability to cooperate and communicate.

Third, the focus and difficulties in teaching

Emphasis: the exploration and simple application of cosine formula of two-angle difference.

Difficulties: the organization and guidance of the exploration process.

Fourthly, the analysis of learning situation.

I have studied the properties of trigonometric functions and the operation and application of plane vectors before. On this basis, we should consider how to express cos(a-β) with sine and cosine values of arbitrary angles A and β, firmly grasp this formula and use it flexibly to learn the next section.

Teaching methods of verbs (abbreviation of verb)

1, autonomous learning method, through self-study to master the cosine formula of the difference between two angles.

2. Inquiry learning, through the process of analyzing, exploring and mastering the cosine formula of the difference between two angles.

3, feedback practice, practice testing the application of knowledge, find out what has not yet been mastered and its gap.

Sixth, preparation before class

1. Students' preparation: preview the cosine formula of two angular differences and understand the reasoning process of the two methods.

2. Teacher preparation: preview the study plan before class, explore the study plan in class and expand the study plan after class.

Seven, the schedule

1 class hour

Eight, the teaching process

Create a scene and reveal the theme. Taking school buildings as background materials, introduce questions. In order to stimulate interest and questions, cos 15 in the question is calculated and evaluated with or without a calculator.