Q111 / 170 · Manipal (MET) 2017 · Mathematics
If the angle between two lines represented by $2 x^2+5 x y+3 y^2+7 y+4=0$ is $\tan ^{-1} m$, then $m$ is equal to
- Correct answerA$1 / 5$
- B$1$
- C$7 / 5$
- D7
Solution
$\begin{gathered} \text { Here, } a=2, b=3, h=\frac{5}{2} \\ \therefore \tan \theta=\frac{2 \sqrt{\left(\frac{5}{2}\right)^2-6}}{2+3} \\ \Rightarrow m=\frac{1}{5}\end{gathered}$
Hence, the correct answer is option: 'A'.