Orthogonal trajectories to a circle

Use the interactive figure to explore different families of orthogonal trajectories to a circle centered at the origin. Drag point [i]R[/i] to change the radius of the circle. Drag point [i]P[/i] to explore the different orthogonal trajectories.
[i]Developed for use with Thomas' Calculus, published by Pearson.[/i]

Information: Orthogonal trajectories to a circle