[填空题]
A particle can move along a straigem*qi-0jk*atjcy1x ( ht line from a point P . The velrzn.5id* :dl kocity v , in :.zrd5d nlk*i$\mathrm{m} \mathrm{s}^{-1}$ , 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} $.≈
