A particle moves with position r(t)=⟨et,e−t⟩\mathbf{r}(t) = \langle e^t, e^{-t} \rangler(t)=⟨et,e−t⟩. What is its velocity at t=0t = 0t=0?
⟨1,−1⟩\langle 1, -1 \rangle⟨1,−1⟩
⟨1,1⟩\langle 1, 1 \rangle⟨1,1⟩
⟨0,0⟩\langle 0, 0 \rangle⟨0,0⟩
⟨e,−e⟩\langle e, -e \rangle⟨e,−e⟩