Q115 / 160 · AP EAMCET 2011 · Mathematics
The angle between the asymptotes of the hyperbola $x^2-3 y^2=3$ is
- A$\frac{\pi}{6}$
- B$\frac{\pi}{4}$
- Correct answerC$\frac{\pi}{3}$
- D$\frac{\pi}{2}$
Solution
Given equation of hyperbola is
$\begin{aligned}
x^2-3 y^2 & =3 \\
\Rightarrow \quad \frac{x^2}{3}-\frac{y^2}{1} & =1
\end{aligned}$
Here, $a^2=3$ and $b^2=1, a>b$.
Now, the equation of asymptote of this hyperbola is,
$\begin{aligned} y & = \pm \frac{b}{a} x \\ \Rightarrow \quad y & = \pm \frac{1}{\sqrt{3}} x\end{aligned}$

Let slope of asymptote (i) is, $m_1=\frac{1}{\sqrt{3}}$ and slope of asymptote (ii) is, $m_2=\frac{-1}{\sqrt{3}}$ Let $\theta$ be the angle between both asymptote, then $\tan \theta=\left|\frac{m_1-m_2}{1+m_1 m_2}\right|=\left|\frac{1 / \sqrt{3}+1 / \sqrt{3}}{1-1 / 3}\right|$ $\begin{array}{cc}\Rightarrow & \tan \theta=\left|\frac{2 / \sqrt{3}}{2 / 3}\right|=\sqrt{3} \\ \Rightarrow & \tan \theta=\tan 60^{\circ} \\ \Rightarrow & \theta=\pi / 3\end{array}$

Let slope of asymptote (i) is, $m_1=\frac{1}{\sqrt{3}}$ and slope of asymptote (ii) is, $m_2=\frac{-1}{\sqrt{3}}$ Let $\theta$ be the angle between both asymptote, then $\tan \theta=\left|\frac{m_1-m_2}{1+m_1 m_2}\right|=\left|\frac{1 / \sqrt{3}+1 / \sqrt{3}}{1-1 / 3}\right|$ $\begin{array}{cc}\Rightarrow & \tan \theta=\left|\frac{2 / \sqrt{3}}{2 / 3}\right|=\sqrt{3} \\ \Rightarrow & \tan \theta=\tan 60^{\circ} \\ \Rightarrow & \theta=\pi / 3\end{array}$
Hence, the correct answer is option: 'C'.