Let the equation of two diameters of a circle $x^{2}+y^{2}-2 x+2 f y+1=0$ be $2 p x-y=1$ and $2 x+p y=4 p$. Then the slope m $\in$ $(0, \infty)$ of the tangent to the hyperbola $3 x^{2}-y^{2}=3$ passing through the centre of the circle is equal to _______________.
Answer (integer)
2
Solution
$$
\begin{aligned}
&2 p+f-1=0 \quad\dots(1)\\\\
&2-p f-4 p=0 \quad\dots(2)\\\\
&2=p(f+4) \\\\
&p=\frac{2}{f+4} \\\\
&2 p=1-f \\\\
&\frac{4}{f+4}=1-f \\\\
&f^2+3 f=0 \\\\
&f=0 \text { or }-3
\end{aligned}
$$<br/><br/>
Hyperbola $3 x^2-y^2=3, x^2-\frac{y^2}{3}=1$<br/><br/>
$\mathrm{y}=\mathrm{mx} \pm \sqrt{\mathrm{m}^2-3}$<br/><br/>
It passes $(1,0)$ <br/><br/>$o=m \pm \sqrt{m^2-3}$<br/><br/>
$m$ tends $\infty$<br/><br/>
$$
\begin{aligned}
&\text {It passes }(1,3) \\\\
&3=m \pm \sqrt{m^2-3} \\\\
&(3-m)^2=m^2-3 \\\\
&m=2
\end{aligned}
$$
About this question
Subject: Mathematics · Chapter: Conic Sections · Topic: Parabola
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