Here's the question you clicked on:
INT
Show that the vector-valued function describes the motion of a particle moving in a circle of radius 1 centered at the point (2,2,1) and lying in the plane x+y-2z=2.
basically this question: http://www.chegg.com/homework-help/questions-and-answers/vector-valued-function-describes-motion-particle-moving-circle-radius-1-centered-point-2-2-q1142004