∴OC'=PC'=PC= 1 1-t.
If p is PE⊥OA in E, PE=BO=6, OE=BP=t,
∴EC'= 1 1-2t.
In Rt△PEC, the equations are listed according to Pythagorean theorem.
.
Solve.
The coordinates of point p are, or.
Comments: The difficulty lies in: (1) discovering PC' = OC(2) constructing a right triangle PEC'', and then making equations according to Pythagorean theorem.