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

JEE Main 2022 (Online) 25th July Morning Shift Mathematics - Straight Lines and Pair of Straight Lines Question 54 English Explanation

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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