EX 11.9 Grove 3u yr 11 Chord of contact question

EX 11.9 Grove 3u yr 11



Formula is $xx_0=2a(y+y_0)$ 

8=4a, so a=2.

$xx_0=2(2)(y+y_0)$

$xx_0=4(y+y_0)$

$4y +4y_0=xx_0$
$4y=xx_0-4y_0$

$y=xx_0/4 - y_0$

Compare to $x+2y-3=0$, which is the same as $y=-x/2 + 3/2$

Comparing gives  $x_0/4=-1/2$  and  $-y_0=3/2$

$x_0=-2, y_0=-1.5$

So Coordinates of $P=(-2,-1.5)$.