What is the unit tangent vector T(t)\mathbf{T}(t)T(t) for r(t)=⟨3t,4t,0⟩\mathbf{r}(t) = \langle 3t, 4t, 0 \rangler(t)=⟨3t,4t,0⟩?
⟨3,4,0⟩\langle 3, 4, 0 \rangle⟨3,4,0⟩
⟨0.6,0.8,0⟩\langle 0.6, 0.8, 0 \rangle⟨0.6,0.8,0⟩
⟨1,1,0⟩\langle 1, 1, 0 \rangle⟨1,1,0⟩
⟨3/7,4/7,0⟩\langle 3/7, 4/7, 0 \rangle⟨3/7,4/7,0⟩