A weight is attached to a spring and reaches its equilibrium position (x = 0). It is then set in motion resulting in a displacement of x = 4 cost, where x is measured in centimeters and t is measured in seconds. See the figure shown to the right. Answer parts (a) and (b). - 4 Equilibrium 0 position at x =0 (a) What is the spring's displacement when t = 0? cm (Type an integer or decimal rounded to one decimal place as needed.)