# Thread: Minimum speed given parametric form of position vector

1. ## Minimum speed given parametric form of position vector

The position function of a particle is given by $\mathbf r(t) = \langle -1 t^2, -2 t, t^2 - 1 t\rangle$.
At what time is the speed minimum?

2. Originally Posted by zpwnchen
The position function of a particle is given by $\mathbf r(t) = \langle -1 t^2, -2 t, t^2 - 1 t\rangle$.