Question 5
The impulse response h(n) was found using the difference equation obtained in question 3. Microsoft Excel was used to obtain numerical results for h(n), for n ranging from 025. The results are tabulated and graphed below.
N

x(n) 
y(n) = h(n) 
2 
0 
0 
1 
0 
0 
0 
1 
0.161 
1 
0 
0 
2 
0 
0.26976 
3 
0 
0 
4 
0 
0.18222 
5 
0 
0 
6 
0 
0.12309 
7 
0 
0 
8 
0 
0.083147 
9 
0 
0 
10 
0 
0.05617 
11 
0 
0 
12 
0 
0.03794 
13 
0 
0 
14 
0 
0.02563 
15 
0 
0 
16 
0 
0.017312 
17 
0 
0 
18 
0 
0.01169 
19 
0 
0 
20 
0 
0.007899 
21 
0 
0 
22 
0 
0.00534 
23 
0 
0 
24 
0 
0.003605 
25 
0 
0 
26 
0 
0.00243 
From the table and graph, it can be calculated that h(n) is less than 1% of its maximum value when n greater than or equal to 22.