Mathematics

Problem

Cars

X

and

Y

travel along a straight highway. Their positions (in kilometers) at time

t

hours are

s_X(t)=t^2+2t

and

s_Y(t)=12t-t^2

, respectively, for

0\le t\le 5

. At what time in this interval are the two cars farthest apart? a)

2\text{ h}

4\text{ h}

2.5\text{ h}

3\text{ h}