The trigonometric functions have features that are worthy of note. Among these features are the period and amplitude. The graph of f(x)=sin x repeats itself along the x-axis by a certain distance. This distance is called the period. For the sine function, the period is 2pi radians. It can also be observed that the graph goes up and then down by a certain distance. This distance is called the amplitude. For the curve of f(x)=sin x, the amplitude is 1.
