Question

If the $x$-intercept of a focal chord of the parabola $y^2=8x+4y+4$ is 3 , then the length of this chord is equal to ___

Answer 1

Answer: 16

$y^2=8x+4y+4$
$(y-2{)}^2=8(x+1)$
$y^2=4ax$
$a=2,X=x+1,Y=y-2$
focus $(1,2)$
$y-2=m(x-1)$
Put $(3,0)$ in the above line $m=-1$
Length of focal chord $=16$