[填空题]
A particle can move along a straight line from a point P .qivow 6 f g;m3hfc069m The ve(gtwmtc ;7,hs:lc0v1cjbk) iw b, v5flocity v , in 7, 5wm bc;bc k ,:ltgj)wci(t0hfvvs1$\mathrm{m} \mathrm{s}^{-1}$ , is given by the function $v(t)=2-e^{-\sin t^{v}} $ where $t \geq 0 $ is measured in seconds.
1. Write down the first two times $ t_{1}$,$ t_{2}>0$ when the particle changes direction.
2. a. Find the time $0\lt t \lt t_{2}$ when the particle has a maximum velocity. ≈
b. Find the time $0\lt t \lt t_{2}$ when the particle has a minimum velocity. ≈
3. Find the distance travelled by the particle between times $t=t_{1}$ and $t=t_{2} $.≈
