Calculate of

and find all the points (x, y) on the curve with horizontal tangent lines.
(not sure how to do this type of problem where they don't give us points. do we use the first derivative test?

David and alton are training for a race. they spend 35 minutes stretching and then go on a 5 mile practice run. david runs at a pace of 7 min/mile. alton runs at a pace of 8 min/mile. write an equation for each runner that shows the total length of their workout. then solve each equation showing your work