(a) Find the slope of the tangent to the asteroid x = a cos3 , y =...

(a) Find the slope of the tangent to the asteroid x = a cos3 θ, y = a sin3 θ in terms of θ. (Asteroids are explored in the Laboratory Project on page 659.)
(b) At what points is the tangent horizontal or vertical?
(c) At what points does the tangent have slope 1 or – 1?