1. (10 pts) For the following systems, determine if they are:
a. Linear
b. Time Invariant
c. Memoryless
d. Causal
e. Stable
f. Invertible
Justify your answers (prove, disprove, or give counter-examples)
i. y(t) = cos(t)x(t)
ii. y(t) = ∫_{-∞}^{2t} x(τ - 1) dτ
iii. y(t) = x(1 - 3t)
iv. y[n] = x[n] - x[n - 2]
v. y[n] = nx[n]