Consider the given information, x=a(t+sin‌t)‌‌‌‌‌⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅(I) And, y=a(1−cos‌t)‌‌‌‌‌⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅(II) Differentiate equation (I) w.r.t t then, ‌
dx
dt
=a(1+cos‌t) Differentiate equation (II) w.r.t t then, ‌