8. [ 3 marks ] A particle moves along a line starting at and returning to the origin every it seconds according to the position function; s(t) = t sint , where t > 0. When t = It, the object is moving ( negative / positive ) direction at exactly units/s b. When t = 2nt, the object is moving ( negative / positive ) direction at exactly units/s c. The solution to "When does the object change direction?" are all the t-coordinates of the points of intersection of y = tant and the line y = mt. State the value of m. 9. [3 marks ] A man standing on a cliff is watching his daughter swim to shore through a telescope. The telescope is 50m above water level and the girl is swimming at 25m/min. At what rate is the angle between the telescope and the cliff changing when she is 50m from shore