Question

A car leaves an intersection traveling east. Its position t sec later is given by
x = t2 + t ft. At the same time, another car leaves the same intersection heading north, traveling
y = t2 + 4t ft in t sec. Find the rate at which the distance between the two cars will be changing 7 sec later. (Round your answer to one decimal place.)

Answer 1

The distance s between the cars at any point of time is \[\sqrt{x ^{2}+y ^{2}}\].
Put the values of x and y in terms of t as given in the question.
After that differentiate this function s with respect to t. Then put t=7 and find the rate of change.
Can you do it yourself now?