The coordinates of a particle moving in a plane are given by `x(t)=a cos (pt)` and `y(t)=b sin (pt)` where a, b `(lt a)` and p are positive constant of appropriate dimensions. Then :

Options

A. the path of the particle is an ellipse
B. the velocity and acceleration of the particle are normal to each other at t p = π/ 2
C. the acceleration of the particle is always directed towards a focus
D. the distance travelled by the particle in time interval t = 0 to t = π / 2 p is a

Answer

A:B:C