4.26. For a spring-mass-damper system with Fext(t) = 20 sin(0.75t) N, m = 10 kg, k = 12 N/m, and b = 10 Ns/m, what is the equation for the steady state sinusoidal response of x(t)? 4.27. A cheap, mechanically actuated, strip chart recording system consisting of a plotter head