For problems 1 and 2, determine if the signal is linear, time-invariant, and/or causal. d'y + say +8y(t) = ax + 3x(t) 1. dt dt t 2. y+ 5y{n-1] = 2x(m+1] 3. A causal linear time-invariant continuous-time system has impulse response h(t) = e" + sin t,t 2 0 Compute the output response for all t>=0 when the input is the unit-step function u(t). 1. For the series RLC circuit shown below, find the input/output differential equation for t= 0 R C i(t) +VR(t ) - +vc(t)- + L -+ VL(t) x(t)