ECS204 Course: Signals and Systems
Jan-Apr IISER Bhopal
2025HW10
1. State the similarities and differences between Fourier transform and Laplace
transform 2. Mention the properties that ROC should satisfy for
1. Right-sided signals
2. Left-sided signals
3. Finite-duration signals
3. Determine the Laplace transform of x(t) = e−tu(t)+e−2tu(t). Also, draw the ROC. Does
the Fourier transform of x(t) exist?
4. Determine the Laplace transform of x(t) = e−atu(t) + ebtu(−t), assuming that a and b
are real such that b > −a. Also, draw the ROC. Does the Fourier transform of x(t) exist?
5. Determine the Laplace transform of the following signals. Also, draw the ROC.
(a) x(t) = δ(t)
(b) x(t) = δ(t + 1) + δ(t − 1)
(c) x(t) = e−atu(t) − u(t − 10)
6. Consider the Laplace transform X(s) of a signal x(t) having three poles at -1,1, and
3. De termine all possible legal ROCs.
7. State True or False
(a) ROC can contain poles of the function X(s) of a signal x(t).
(b) ROC comes in strips in the s-plane.
(c) ROC is a connected region in the s-plane.
(d) Fourier transform is Laplace transform evaluated on the jω axis.
8. If x(t) ↔ X(s) are Laplace transform pairs, then show that
(a) x(t − t0) ↔ e−st0X(s)
(b) es0tx(t) ↔ X(s − s0)
(c) ddtx(t) ↔ sX(s)
t
(d) R −∞ x(τ )dτ ↔ X(s)
s
(e) x(−t) ↔ X(−s)