**Use MatLab to make function**

Write a function that synthesizes a sinusoid at any specified sampling rate, amplitude, frequency, starting phase, and duration. It should take these parameters as arguments, and return the signal as well as its length in samples. Then, write a script that uses your function 3 times in order to create 3 sinusoids of different durations, frequencies, ampli- tudes, and phases, and mix them down into a single channel (they should all have the same sampling rate though). The script should also plot the 3 individual sinusoids as well as the mixdown in a single figure window by using subplot(), and export 4 separate mono .wav files. Remember to normalize the mixdown into the standard -1.0 to 1.0 audio signal range.