Answer:
The command i will use in carrying out such function is 
Explanation;
Kindly check the attached file for the command as it can not be written fully in the answer box.
 
        
             
        
        
        
Answer:
Option A) Demand for CDs has decreased, causing equilibrium price and quantity to decrease.
is the correct answer.
Explanation:
- File-sharing is a common practice nowadays. It helps us by providing access to different files (audio , video, images, documents) to others in a faster way.
- A wide range of files are shared daily by using different means of file-sharing including computer networks and peer-to-peer networking.
- Formerly, the data was shared using CDs but now this system has been replaced with the advent of internet. 
- Usage of CDs is dropped drastically and hence their demand is decreased.
- So now the prices of CDs are not in equilibrium and their quantity is also decreased.
i hope it will help you!
 
        
             
        
        
        
Answer:
Explanation:
try
clc
clear
close all
x=linspace(0,2*pi,7);
z=cos(pi.*x./3)
% the output on mine is to 4 decimals so it looks a bit different than what the output on your example is , but, I think if you change the format to decimal 2 it will look the same  :)
 
        
             
        
        
        
decibels i believe is the correct answer. hope it helps :)