[填空题]
The downward speed, V, in metdn rxg:.k em62vyzm 5,hxkf 8o8v4 cw*res per second, gaingesd0 0:l/)bwp 0g; eoc1 raquo) sz5ww/al 5ped by a skydiver during a jump is modelled b :wgwl ;00pe1)a /og/ou)qrlp ac0 5essdz bw5y the function
V(t)=56−56$\times3$$^{-\frac{t}{4}}$,t≥0,where t, in seconds, is the time for which the skydiver is free falling in the air.
1.Write down the downward speed of the skydiver at t=0.
The line L is the horizontal asymptote to the graph. V =
2.Determine the equation of L.
The skydiver starts to feel no acceleration when he reaches the speed of 55 metres per second. y =
3.Find the time it takes for the skydiver to reach this speed. Give your answer correct to the nearest second. t ≈