Sketch the output response for below process models when they are subjected

to a unit step change in the input. Sketch all three $(3)$ output responses in ONE

single plot.

a$.,G_1(s)=\frac{4}{s^2+s+1}$

b$.,G_2(s)=\frac{3}{4s^2+8s+1}$

c$.,G_3(s)=\frac{2e^{-5s}}{2s+1}$