Trigonometric Functions
 

 

 

Contents

 

Trigonometric Functions

 

Basic Functions

 

Reciprocal Functions

 

Inverse Functions

 

Scaling

 

Translation

 

Reflection

 

Quiz

 

Geometry Main Page 

Trigonometric Functions
 
 
The definitions and manipulation of trigonometric functions can be found in our section on trigonometry.
 
In this section, we are concerned with graphs of trigonometric functions. We will introduce the shape of the graphs, discuss the properties of the graphs as well as demonstrate the transformation of their graphs.
 
Definitions
There are some terms commonly used in the description of trigonometric functions.
 
Period : The interval over which the graph of a function repeats itself.
Peak : The maximum value of a function. In this section, it is applicable only to the sine and cosine curves.
Trough : The minimum value of a function. In this section, it is applicable only to the sine and cosine curves.
Amplitude : The largest deviation from the zero point which the curve can reach
Frequency : The number of periods that occurs in 360o.
 
The graphs here are in degrees, do note that it can be converted to radians.
 
Applications
The sine and cosine curves appear in nature. Transverse waves follow this shape (note that the sine and cosine curves are basically translations of each other). The representation of sound waves on a cathode-ray oscilloscope also follow this shape. Another common example is the graph of the voltage of the alternating current output in a generator.
 
Tangent and the reciprocal function graphs are rarely seen.
 
 
Most of the graphs in this section are the drawings of our coach, Mr. Lim Poh Kheng. Used with permission.