Runner A starts at the origin and runs east at

MATHEMATICS · Subjective · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation

Problem

5\text{ m/s}

. Runner B starts

20\text{ m}

north of the origin and runs south along the

y

-axis at

2\text{ m/s}

. Let

t=0

when the runners start. Determine the time

t

(in seconds) at which the distance between the runners is minimized.