First of all, let's take a look at the important test sites of trigonometric function, or what important knowledge points students need to master.
Popularization of the concept of angle; Curvature system; Trigonometric function at any angle; The trigonometric function line in the unit circle; Basic relations of trigonometric functions with the same angle; Inductive formulas of sine and cosine; Sine, cosine and tangent of sum and difference of two angles; Sine, cosine and tangent of double angles; Images and properties of sine function and cosine function; Periodic function; The image of function y=Asin(ωx+φ); Images and properties of tangent function; Find the angle with the known trigonometric function value; Sine theorem; Cosine theorem; Oblique triangle connection.
Say it, then why do many students find trigonometric functions more difficult? There are three main reasons:
1, there are countless formulas of trigonometric functions, which are hard to remember and easy to be confused or misused.
2. When transforming the function image, the influence of the sequence of periodic transformation and translation transformation on the translation quantity is confused.
3. How to choose and use formulas to solve the problem of trigonometric identity transformation from different angles, their interrelationships and different function names?
For the trigonometric function, I suggest dividing it into two modules. The geometric part includes various identical transformation formulas and the subsequent solution of trigonometry, and the algebraic part is mainly the images and properties of trigonometric functions. In the part of geometry, I have summarized some conclusions and formulas that will be used in the college entrance examination, so I must use them skillfully.
Basic knowledge such as the image and properties of trigonometric functions, the relationship between trigonometric functions with the same angle, the sum and difference formula of two angles, and the double angle formula. , to investigate the basic computing ability, and the idea of combining numbers with shapes, simplifying and transforming.
Share it with you first, and if necessary, you can also sort out some classic exercises for you, and then see how the feedback from the students works ~