# Math Help - Minimum speed given parametric form of position vector

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

Please help with this one

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
Please help with this one

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?
Can you find the velocity vector? Can you get the speed from this? Please show all your working and state where you get stuck.