Q105 / 155 · WBJEE 2024 · Mathematics
The locus of the midpoint of the system of parallel chords parallel to the line $y=2 x$ to the hyperbola $9 x^2-4 y^2=36$ is
- A8x - 9y = 0
- Correct answerB9x - 8y = 0
- C8x + 9y = 0
- D9x - 4y = 0
Solution
Hint : Locus implies diameter of the hyperbola
$\begin{aligned}
& \text {i.e. } y=\frac{b^2}{a^2 m} x \quad(m=2) \\
& \Rightarrow y=\frac{9}{8} x \\
& \Rightarrow 9 x-8 y=0
\end{aligned}$
Hence, the correct answer is option: 'B'.