Two cars start driving from the same point. One travels north at30 miles per hour, and the other travels east at 45 miles per hour.At what rate is the distance between the cars increasing two hourslater?
(a) Draw a diagram, label quantities.
(b) Write rates as derivatives.
(c) Find an equation involving the quantities; differentiate on bothsides with respect to t.
(d) Plug in known information and solve for the unknown. [As usual,numeric simpliï¬cation not required.]
