he graph from the US Department of Energy shows how driving speed affects gas mileage Fuel economy F is measured in miles per gallon and speed v is measured in miles per hour F mi gal 30 y 20 10 1 0 10 20 30 40 50 60 a What is the meaning of the derivative F v O F v is the instantaneous rate of change of speed with respect to fuel economy O F v is the instantaneous rate of change of distance with respect to speed b Sketch the graph of y F v 70 mi h O F v is the instantaneous rate of change of fuel economy with respect to speed OF v is the instantaneous rate of change of speed with respect to distance O F v is the instantaneous rate of change of fuel economy with respect to distance 10 20 10 20 30 40 50 60 70 pergales V V 70 10 70 V 10 20 30 40 50 60 G 20 30 40 50 60 30