Identify the function which represents a non-periodic motion.
- ( t + /4)
- e- t
- t
- t + t
Answer
(2) e- t
Solution
A periodic function repeats itself after a fixed interval: f(t + T) = f(t).
( t + /4), t and t + t = 2 ( t + /4) all repeat with period T = 2 .
e- t decreases continuously with time and never repeats its value non-periodic.
Answer: (2)