Halley's comet travels in an ellipti- cal orbit with a = 17.95 and b = 4.44 and passes by Earth roughly every 76 years. Note that each unit represents one astronomical unit, or 93 million miles. The comet most recently passed by Earth in February 1986.

(a) Write an equation for this orbit, centered at (0, 0) with major axis on the x-axis. 

(b) If the sun lies (at the focus) on the positive x-axis, approximate its coordinates. 

(c) Determine the maximum and minimum distances between Halley's comet and the sun.