So 0 = a? b？ 35= 16a+4b？ 3,
A = 1b =？ 2,
The expression of parabola is y=x2-2x-3.
The symmetry axis is a straight line x= 1,
According to the meaning of the question, if the analytical formula of straight line BC is y=kx-3, then 5=4k-3 and k=2,
The analytical formula of line BC is y=2x-3,
∴p( 1,- 1)；
(2) Move parabola ① to the right by 1 unit, and then move it up by m units to get parabola ②.
The expression of parabola ② is y=(x- 1- 1)2-4+m,
∵ parabola ② passes through point P,
∴- 1=( 1- 1- 1)2-4+m，
∴m=2，
∴ Move it up by 2 units to get a parabola ②;
(3)∵ Parabola ① moves to the right by 1 unit, and then moves up by 2 units to get parabola ②,
The expression of parabola ② is y=(x- 1- 1)2-4+2, that is, y=(x-2)2-2.
∴D(2,-2),E(0,2)，
∫P( 1，- 1)，
∴ The straight line DP passes through the point O, and the included angle with the X axis is 45.
After passing through point e, it becomes EH⊥DP at point h,
∴∠EOH=45，
∫E(0，2)，
Eh = 2，ED=22+(2+2)2=25，
∴sin∠EDP=EHDE