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 (integer)
16
Solution
$$
\begin{aligned}
& y^2=8 x+4 y+4 \\\\
& (y-2)^2=8(x+1) \\\\
& Y^2=4 a X \\\\
& a=2, X=x+1, Y=y-2 \\\\
& \text { focus }(1,2) \\\\
& y-2=m(x-1)
\end{aligned}
$$
<br/><br/>Put $(3,0)$ in the above line $\mathrm{m}=-1$
<br/><br/>Length of focal chord $=16$
About this question
Subject: Mathematics · Chapter: Conic Sections · Topic: Parabola
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