Suppose a weight is attached to a spring and bobs up and down, exhibiting symmetry. Suppose the graph of the displacement function is shown in the graph below, where the values on the :1\": axis represent the time in seconds and the yaxis represents the displacement in inches. Give the equation that models the vertical displacement of the weight on the spring. i'NUJJE-WO'I 5 6 Y 8 9 1'1,112131,415