A particle moves in the plane with position vector meters for

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

Problem

A particle moves in the plane with position vector

\mathbf r(t)=\langle t\cos t,\;t\sin t\rangle

meters for

0\le t\le 2\pi

. Determine the value of

t

in this interval at which the particle’s speed is minimized.