In high school, we learned the definition of trigonometric functions , the domain of trigonometric functions and the symbols of function values , trigonometric function lines , graphical properties of sine functions , graphical properties of cosine functions , graphical properties of tangent functions , and commonly used images of trigonometric functions Transformation etc.  As commonly used basic elementary functions, we summarize the graphics and properties of trigonometric functions as follows.

　　Graphs and properties of trigonometric functions :

　　1. The sine function has a domain of

,

the value range is , odd functions and periodic functions with as the period (Figure 1).

Figure 1 ：[ Animation ]

　　2. The cosine function has a domain of

,

The value range is , even functions and periodic functions with as the period (Figure 2).

Figure 2 ：[ Animation ]

　　3. The tangent function has a domain of

,

The value range is , odd functions and periodic functions with as the period (Figure 3).

Figure 3 ：[ Animation ]

　　4. The cotangent function has a domain of

,

The value range is , odd functions and periodic functions with as the period (Figure 4).

Figure 4 ：[ Animation ]

　　In addition, commonly used trigonometric functions include:

Secant function ; 

Cosecant function .