QJEEAdv08Ma7470: JEE Advanced 2008 Mathematics - Class 12 JEEAdv08Ma7470 Solution: The distance of the point from the plane passing through the…

The equation of the plane passing through the point ( $-1,-2,-1$ ) and whose normal is perpendicular to both the given lines L $_1$ and L $_2$ written as

$(x + 1) + 7(y + 2) - 5(z + 1) = 0$

i.e., $x + 7y - 5z + 10 = 0$

The distance of the point (1, 1, 1) from the plane

$= \left| {{{1 + 7 - 5 + 10} \over {\sqrt {1 + 49 + 25} }}} \right|$

$= {{13} \over {\sqrt {75} }}$ units