2. Bring d into the equation so that m=3 or m=- 1 (s).

D (3,4) is obtained.

B (4,0) is obtained by solving the equation.

The BC equation is y = 4-X.

Let E(x, y)

There is a DE midpoint on the BC line.

Get (3+x)/2+(4+y)/2=4①。

The product of DE slope and BC is-1.

Get it at once

(y-4)/(x-3)= 1②

E(0, 1) from ① ②

3.BD slope is k=

-

four

=tanθ

Let BP slope k = tan (θ+45) or k = tan (θ-45).

Get the BP slope k value.

We also know the point b (4,0), and get the BP straight line, and then the point p connected with the parabola.

I don't need to say anything else.