1. Basic operation ability: Learning trigonometric functions requires mastering four basic operations, including addition, subtraction, multiplication, division and power operation. These operations are the basis of solving trigonometric function problems.
2. Algebra knowledge: learning trigonometric functions requires understanding the basic concepts of algebra, such as real numbers, complex numbers, equations, inequalities, etc. In addition, we should master the solution of quadratic equation in one variable, because trigonometric function is closely related to quadratic equation in one variable.
3. Geometry knowledge: Learning trigonometric functions requires understanding the basic concepts of geometry such as points, lines, surfaces and angles. In addition, we need to master the properties of right triangle, such as Pythagorean theorem, sine theorem, cosine theorem and so on. These geometric knowledge is the basis of understanding the properties of trigonometric functions.
4. Definition and properties of trigonometric functions: Learning trigonometric functions requires understanding the definition and properties of trigonometric functions, such as sine function, cosine function and tangent function. These definitions and properties are the key to solve the trigonometric function problem.
5. Images and properties of trigonometric functions: Learning trigonometric functions requires understanding the images and properties of trigonometric functions, such as periodicity, parity and monotonicity. These images and properties help us to better understand and apply trigonometric functions.
6. trigonometric identities: learning trigonometric functions requires mastering some basic trigonometric identities, such as addition and subtraction formulas, double-angle formulas, and half-angle formulas. These identities can help us simplify the trigonometric function expression, and thus solve the problem more easily.
7. Application of trigonometric function: Learning trigonometric function requires understanding the application of trigonometric function in practical problems, such as physics, engineering, economy and other fields. These applications can help us better understand the practical significance of trigonometric functions.
In a word, learning trigonometric functions needs certain mathematical foundation, including basic calculation ability, algebra knowledge, geometry knowledge, definition and properties of trigonometric functions, images and properties, trigonometric identities and applications. Only by mastering these basic knowledge can we learn and understand trigonometric functions better.