As shown in the figure, in the plane rectangular coordinate system, the straight line Y = intersects the X axis and the Y axis at point A and point B respectively, and rotates △ABO clockwise around the origin O to get △A? 0? 7B？ 0? 7O, and do OA? 0? 7⊥AB, vertical foot is D, straight line AB and line segment A? 0? 7B？ 0? 7 intersects at the G point, and the moving point E starts from the origin O and moves along the positive direction of the X axis at the speed of 1 unit/second. Let the moving time of the moving point e be t seconds.

(1) Find the coordinates of point D;

(2) Connect DE when DE and segment OB? 0? 7 intersect, the intersection point is f, quadrilateral DFB? 0? When 7G is a parallelogram, (as shown in Figure 2) find the analytical formula of the straight line where the line segment DE is located at this time;

(3) If the fixed point is the center of E and the radius is ⊙E, then connect A? 0? 7E, when is t? Tan∠EA？ 0? 7B？ 0? 7= ? And judge the straight line a at this time? 0? Please explain the positional relationship between 7O and ⊙ E.