Sketch the following exponential waveforms. Find the amplitude and time constant of each waveform.

(a) \(v_{1}(t)=5 e^{-2 t} u(t) \mathrm{V}\)

(b) \(v_{2}(t)=5 e^{-2 t} u(t-1) \mathrm{V}\)

(c) \(v_{3}(t)=5 e^{-2(t-1)} u(t) \mathrm{V}\)

(d) \(v_{4}(t)=5 e^{-2(t-1)} u(t-1) \mathrm{V}\)