Trigonometric+Functions+and+Graphs


 * Trigonometric functions**

"There exist a category of functions, known as the **circular trigonometric functions **, that possess an interesting property - that of periodicity. That is, they behave in such a way that their values are repeated over and over. This is known as **periodic** behaviour. Many real world phenomena are periodic in the sense that the same patterns repeat over time. The **circular trigonometric functions ** (or simply trigonometric functions) are often used to model such phenomena which include sound waves, light waves, alternating current electricity and other more approximately periodic events such as tides and even our moods (i.e. biorythms)."


 * What do trigonometric functions look like?**

The three functions that we shall consider are the sine function, the cosine function and the tangent function. Their graphs for values of x between 0 and 2pi inclusive can be seen below: Source: http://www.math.com/tables/graphs/trig.htm

Watch the following video and note some of the features of trigonometric functions: media type="youtube" key="FUMpGuLIQ5M" height="344" width="425"