The horsepower H required to overcome wind drag on a particular automobile is given by
H(x) = 0.00004636x3

where x is the speed of the car (in miles per hour).
(a) Use a graphing utility to graph the function.
(b) Rewrite the horsepower function so that x represents the speed in kilometers per hour. [Find H(x/1.6).] Identify the type of transformation applied to the graph of the horsepower function