Substitute ellipse: (4k square +3)x square -8k square x+4k square-12=0.

Let p (x 1, y 1) and q (x2, y2).

Linear AP: y = (x+2) * y1/(x1+2)

Let x=4 and get the coordinates of n points [4,6y1/(x1+2)].

NR slope: 3y 1/(x 1+2)

QR slope: (-y2)/(2-x2)

Two slopes are subtracted: 3y1/(x1+2)+y2/(2-x2) = (6y1-3y1x2+x1y2+2y2)/[

6y 1-3y 1x 2+x 1 y2+2 y2 = 6k(x 1- 1)+3k(x 1- 1)x2+x 1 * k(x2- 1)+2k(x2- 1)= 5k(x 1+x2)-2kx 65448

Where x 1+x2=8k square /(4k square +3), x 1x2=(4k square-12)/(4k square +3).

Substitute into the above formula =0

So the NRQ three-point line.