t3 4t2 + 12t+3 fort > 0, 3 A train travels along a set of tracks according to the function s(t) where t is measured in seconds and s is measured in meters. On what interval(s) is the train moving to the left? = (Enter your answer in interval notation. If entering more than one interval write the intervals as a union.) The value of s(t) is increasing to the right and decreasing to the left. Provide your answer below: