x = a^2 cos t
y = b^2 sin t
(a) Find the time taken of the first time that P reaches the original position.
(b) Find the speed of P when it reaches the original position.
更新1:
(c) There are two points A and B such that the sum of the length of AP and BP is always the same. ˉ(i)Find the coordinates of A and B. ˉ(ii)Find the distance between A and B. ˉ(iii)Find the sum of the length of AP and BP.
更新2:
(e) Express the included angle θ of AP and BP in term of a, b and t. (f) Find the rate of change of θ when P reaches the original position.
更新3:
更正，是： x = a cos t y = b sin t
