1. Sine and cosine curves represented by rectangular coordinate equation _ _ = _ _ _ _ _ _ _ _ _ _.

2. The parametric equation _ _ = _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ∈ represents the spatial curve.

4. Make the figure of cycloid.

5. Make a parameter equation _ = _ 0.25 _ _ _ _ _ _ _ _ _ 0.25 _ _ _ _ _ _ _ _ 0.25 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. _ _ 0.25 _ _ _ _ _ _ _ _ 0.25 _ _ _ _ _ _ _ _ 0.25 _ _ _ _ _ _ _ _ 0.25 _ _ _ _ _ _ _ _ 0.25 _ _ _ _ _ _ _ _ 0.25。