Chegg keeps getting this answer wrong....

ctice: Applications of the Derivativ Question 9, 27.1.53 HW S

ctice: Applications of the Derivativ < Question 9, 27.1.53 > The displacement d (in mm) of a piano wire as a function of the time t (in s) is given by d = 3.0 sin 168t cos 168t How fast is the displacement changing when t = 30 ms? The change in displacement is mm's when t= 3.0 ms. (Do not round until the final answer. Then round to the nearest whole number as needed.)