A particle moves in the plane with velocity for

MATHEMATICS · Single correct · AP · Calculus BC · Parametric, Polar, and Vector-Valued Functions · Parametric, Polar, and Vector-Valued Functions

Problem

A particle moves in the plane with velocity

\mathbf v(t)=\langle t^{2}-4,\, 2t\rangle

for

-3\le t\le 3

. For how many values of

t

in this interval is the particle’s speed neither increasing nor decreasing? (a)

2

(b)

4

(c)

3

(d)

1