[填空题]
An object is moving along a straight line from a point $\mathrm{P}$ . The velocity v , in $\mathrm{m}$ $\mathrm{s}^{-1} $, is given by the function v(t)=2-$e^{-\sin t^{3}}$ where t \geq 0 is measured in seconds.
1. Write down the first two times $ t_{1}$, $t_{2}>0$ when the object changes direction.
t≈ and 1.77 sec
2. 1. Find the time 0 2 . Find the time 0 3. Find the distance travelled by the object between times t=$t_{1}$ and t=$t_{2}$ .
d≈ m (four decimal places)
