Consider a continuous time system A, modelled by the equation y(t) = t x(t) + 4 and a discrete time system B modelled by the equation y[n] = x2[n]. These systems are
1
A-time invariant and B-time invariant
2
A-time varying and B-time invariant
3
A-time invariant and B-time varying
4
A-time varying and B-time varying