1.3-3 Determine whether each of the following statements is true or false. If the statement is false, demonstrate this by proof or example. (a) Every continuous-time signal is an analog signal. (b) Everydiscrete-. (c) If a signal is not an energy signal, then it must be a power signal and vice versa. (d) An energy signal must be of finite duration. (e) A power signal cannot be causal. (f) A periodic signal cannot be anticausal

(a)False (b)False (c)False (d)False (e)False

Explanation:

a) Continuous time signal can also be digital. e.g continuous time square waveform (see first picture)

b) A discrete time signal can also be analog. e.g discrete time exponential function can take any value (see second picture)

c) When both energy and power of signal are infinite, it is neither power signal nor energy signal e.g ramp signals, signal

d)A signal of infinite length can also have finite energy. e. g

e)Step waveform u(t) is a power signal but also causal

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

: )