Four continuous-time signals have the following descriptions.

Question

Answer the following questions



1. Which continuous-time signals are even functions?

2. Which continuous-time signals are not even but can be made even by adding or subtracting a constant?

3. Which continuous-time signals are odd functions?

4. Which continuous-time signals are not odd but can be made odd by adding or subtracting a constant?

5. Which continuous-time signals have an average value of zero?

6. Which of the continuous-time signals are square waves?

7. What is the average signal power of x1(t) ?

8. What is the average signal power of x4(t) ?

Answer 1

1. Which continuous-time signals are even functions? 1



2. Which continuous-time signals are not even but can be made even by adding or subtracting a constant? none



3. Which continuous-time signals are odd functions? 2, 4



4. Which continuous-time signals are not odd but can be made odd by adding or subtracting a constant? 3

5. Which continuous-time signals have an average value of zero? 1, 2, 4



6. Which of the continuous-time signals are square waves? 1



7. What is the average signal power of x1(t) ?



This is a square wave alternating between +3 and –3. Its square is a constant +9. Therefore its average signal power is 9.



8. What is the average signal power of x4(t) ?

By Parseval’s theorem, the average signal power is the sum of the squares of the magnitudes of the impulse strengths in the harmonic function. For this signal