The sine function can be used to create a signal with a single frequency called a sine wave. This signal is commonly used in audio as a test signal to analyze various processing effects.
There is a function in Matlab for synthesizing a sine wave. The basic syntax for using the function is the following:
[y] = sin(2 * pi * f * t)
Input Variables:
f – frequency of the signal (scalar in Hz)
t – an array of time samples for a signal.
Output Variable:
y – an array containing a sine-wave signal.
Further documentation for the function is available here.
A sine wave is defined by three characteristics: frequency, amplitude, and phase. The follow table describes how to use the sine function to create a sine wave and specify these characteristics. Let’s assume we are concerned with how the sine function changes over units of time, 
The sine wave is a special signal because it only contains one frequency. Therefore, it can be used as a reference and to make measurements. Besides the sine wave, there are other test signals which contain more than one frequency. Next, let’s look at the square wave.