Use the parametric equations x = a( - sin) and y = a(1 - cos ), a

Use the parametric equations x = a(θ - sinθ) and y = a(1 - cos θ), a > 0 to answer the following.
(a) Find dy/dx and d²y/dx².
(b) Find the equation of the tangent line at the point where θ = π/6.
(c) Find all points of horizontal tangency.
(d) Determine where the curve is concave upward or concave downward.
(e) Find the length of one arc of the curve.