1.  Each system in the cascade is individual of causal and unstable

3.  at least one system is causal and all the systems are unstable

4.  The majorities are unstable and the majorities are causal.

2.  x(t) has average value because it is periodic

3.  The imaginary part of x(t) is constant

4.  The real part of x (t) is even.

1.  y(n) is non-causal with finite support

2.  y(n) is causal with infinite support

3.  y(n)=0;|n|>3

4.  Re[Y(z)]z=ejθ=-Re[Y(z)]z=ejθ

1.  0.4 Πs

2.  0.8 Πs

3.  1.25 Πs

1.  Linear and causal

3.  Causal but not linear

4.  Neither linear nor causal.

2.  1

3.  

4.  

1.  A minimum

2.  A discontinuity

3.  A point of inflection

1.  2.

2.  2Π

3.  4

1.  h[n]={1, 0, 0, 1}

2.  h[n]={1, 0, 1}

3.  h[n]={1, 1, 1, 1}

4.  h[n]={1, 1, 1}

1.  g(t)=f(2t-3)

2.  

3.