JEE MAIN - Mathematics (2022 - 25th July Morning Shift - No. 12)
A line, with the slope greater than one, passes through the point $$A(4,3)$$ and intersects the line $$x-y-2=0$$ at the point B. If the length of the line segment $$A B$$ is $$\frac{\sqrt{29}}{3}$$, then $$B$$ also lies on the line :
$$2 x+y=9$$
$$3 x-2 y=7$$
$$ x+2 y=6$$
$$2 x-3 y=3$$
Explanation
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Let inclination of required line is $\theta$,
So the coordinates of point $B$ can be assumed as
$\left(4-\frac{\sqrt{29}}{3} \cos \theta, 3-\frac{\sqrt{29}}{3} \sin \theta\right)$
Which satisfices $x-y-2=0$
$4-\frac{\sqrt{29}}{3} \cos \theta-3+\frac{\sqrt{29}}{3} \sin \theta-2=0$
$\sin \theta-\cos \theta=\frac{3}{\sqrt{29}}$
By squaring
$\sin 2 \theta=\frac{20}{29}=\frac{2 \tan \theta}{1+\tan ^{2} \theta}$
$\tan \theta=\frac{5}{2}$ only (because slope is greater than 1 )
$$ \sin \theta=\frac{5}{\sqrt{29}}, \cos \theta=\frac{2}{\sqrt{29}} $$
Point $B:\left(\frac{10}{3}, \frac{4}{3}\right)$
Which also satisfies $x+2 y=6$
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