Determine whether each of the following statements concerning LTI systems is true or false. Justify your answer.

(a) If is the impulse response of an LTI system and is periodic and nonzero, the system is unstable.

(b) The inverse of a causal LTI system is always causal.

(c) If for each n , where K is a given number, then the LTI system with as its impulse response is stable.

(d) If a discrete - time LTI system has an impulse response of finite duration, the system is stable.

(e) If an LTI system is causal, it is stable.

(f) The cascade of a non causal LTI system with a causal one is necessarily non - causal.

(g) A continuous - time LTI system is stable if and only if its step response is absolutely integrable, that is, if and only if  

(h) A discrete - time LTI system is causal if and only if its step response is zero for .