The black line is the graph of y= x. Which of these equations could represent the blue line?
yt

y = 0.001x
y = 2x
y = -x
y = 1/2x

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).