4. Now, modify the m-file by adding commands to it to scale the amplitude of the cosine function by a factor of 2. Then, without overwriting the existing cosine waves,

generate new cosine waves with amplitude scaling factors 3 and 4, respectively. Make a single figure that contains the plots of all the four cosine wave versions (with amplitude scaling factors 1(this is the original cosine), 2, 3 and 4 respectively).