Mathematics

Problem

Let

r(t)=\langle t^{3}-3t,\; t^{2}-4\rangle

denote the position of a particle for

0\le t\le 3

(time in seconds). For which value of

t

in this interval is the particle’s speed minimized? a)

t=1

t=0

t=\dfrac{\sqrt7}{3}

t=\dfrac{3}{2}