The square of the distance of the point of intersection
of the line ${{x - 1} \over 2} = {{y - 2} \over 3} = {{z + 1} \over 6}$ and the plane $2x - y + z = 6$ from the point ($-$1, $-$1, 2) is __________.
Answer (integer)
61
Solution
${{x - 1} \over 2} = {{y - 2} \over 3} = {{z + 1} \over 6} = \lambda$<br><br>$x = 2\lambda + 1,y = 3\lambda + 2,z = 6\lambda - 1$<br><br>for point of intersection of line & plane<br><br>$2(2\lambda + 1) - (3\lambda + 2) + (6\lambda - 1) = 6$<br><br>$7\lambda = 7 \Rightarrow \lambda = 1$<br><br>point : (3, 5, 5)<br><br>(distance)<sup>2</sup> = ${(3 + 1)^2} + {(5 + 1)^2} + {(5 - 2)^2}$<br><br>$= 16 + 36 + 9 = 61$
About this question
Subject: Mathematics · Chapter: Three Dimensional Geometry · Topic: Direction Cosines and Ratios
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