Topic: Grand finale; Ordinary type.

Analysis: As can be seen from the figure, there are six points in a cycle, so the coordinates of P7 are the same as those of P 1, and the coordinates of P 100 are the same as those of P4, which can be quickly found through the points in the figure.

Solution: Solution: As shown in the figure:

The coordinates of P2 are (1,-1), P7 is (1, 1), and P 100 is (1, -3).

Reason: Taking P 1 as the symmetrical point of point A, we can get P2( 1,-1). By analyzing the meaning of the question, we can know a six-point cycle.

Therefore, the coordinates of P7 are the same as those of P 1, and the coordinates of P 100 are the same as those of P4.

So the coordinates of P7 are equivalent to P 1 (1, 1), and the coordinates of P 100 are equivalent to the coordinates of P4 (1, -3).

So the answer is: (1, -3).

Comments: This question examines the knowledge of central symmetry, coordinates and graphic properties, which belongs to a regular type and has certain difficulty. The key to solve this problem is to understand the meaning of the topic, draw a graph, observe and analyze it carefully, and get the corresponding laws.