Somebody help please

The graph below could be the graph of which exponential function?

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

An air conditioning system can circulate 350 cubic feet of air per minute. how many cubic yards of air can it circulate per minute?