Q. The angle between the lines in $x^{2} - xy - 6y^{2} - 7x + 31y - 18 = 0$ is
A) $60{^\circ}$
B) $45{^\circ}$
C) $30{^\circ}$
D) $90{^\circ}$
Explanation
(b)
$Here,\ h = - \frac{1}{2},\ a = 1,\ b = - 6$
$\therefore\tan = \left| 2\frac{\sqrt{\frac{1}{4} + 6}}{1 - 6} \right| = \frac{2\sqrt{\frac{25}{4}}}{- 5} = | - 1|$
$\therefore\ \theta = \tan^{- 1}(1) = 45{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.