Page 47 - Schaum's Outline of Theory and Problems of Signals and Systems

SIGNALS AND SYSTEMS [CHAP. 1

(c) By Eq. (1.26)
x(t)s(t - 3) =x($)s(t - $) = 26(t - $)

which is sketched in Fig. 1-28(c).

(c)
Fig. 1-28

1.23. A discrete-time signal x[n] is shown in Fig. 1-29. Sketch and label each of the
following signals.

(a) x[n]u[l - n]; (b) x[n](u[n + 21 - u[n]}; (c) x[n]6[n - 11

-4-3-2-1 0 12 3 4 5 n
Fig. 1-29

(a) By definition (1.44)

and x[n]u[l - n] is sketched in Fig. 1-30(a).