Construct the line segments joining points of the curve with the corresponding center of curvature for each of the following: thenephroid, the astroid, the deltoid and the cardioid.
7-8 The cycloid:(t+sint,cost)
7-9 The ellipse (5cost,3sint)
7-10 The ":egg": (5cost-2cost,3sint-sin(2t))
7-13 spiral
7-6 The deltoid :(2cost+cos2t,2sint-sin2t)
