Answer:
1. Discrete-time signals are represented mathematically as sequences of numbers. A sequence of numbers x, in which the nth number in the sequence is denoted x[n],
1 is
formally written as
x = {x[n]}, −∞ <n< ∞, (2.1)
2. where n is an integer. In a practical setting, such sequences can often arise from periodic
sampling of an analog (i.e., continuous-time) signal xa(t). In that case, the numeric value
of the nth number in the sequence is equal to the value of the analog signal, xa(t), at
time nT : i.e.,
x[n] = xa(nT ), −∞ <n< ∞. (2.2)
Step-by-step explanation:
