A woman attached to a bungee cord jumps from a bridge that is 42 m above a river. Her height in meters above the river t seconds alter the jump is ym=21(1+ e 'lcoet),fort20_ 3. Determine her velocity at t =1 and t=3. b. Use a graphing utility to determine when she is moving downward and when she is moving upward during the rst '10 s. c. Use a graphing utility to estimate the maximum upward velocity