6. A spectator at the Reno Air Show Races (where vintage WW II aircraft fly very close to the ground on a triangular course passing by three pylons) watches a P51D Mustang passing straight and level at a constant 540 kilometers per hour in front of her. At its closest approach, the plane will be 600 meters away from her. Let 0 be the angle between the spectator's line of sight and a line perpendicular to the drag strip; and let x be the horizontal distance from the plane to that line (in km). a) [4] Find the rate of change of 0, do , when the plane is 600 m from the nearest dt point (i.e., when x = 0.6km). [HINT: tane = ] 0.6 b) [3] What is the maximum value of the rate of change of the angle e. do ? Explain fully. dt