Mathematics · 3D Geometry

JEE Main 2024 — 31 January, Shift 2 — Question 26

A line passes through A(4,−6,−2)A(4,-6,-2) and B(16,−2,4)B(16,-2,4). The point P(a,b,c)P(a, b, c) where a,b,ca, b, c are non-negative integers, on the line ABA B lies at a distance of 21 units, from the point A . The distance between the points P(a,b,c)P(a, b, c) and Q(4,−12,3)Q(4,-12,3) is equal to \qquad .

Answer: 22

Numerical answer — enter this value.

Step-by-step solution

x−412=x+64=z+26\begin{aligned} & \frac{x-4}{12}=\frac{x+6}{4}=\frac{z+2}{6} &\end{aligned}

x−467=y+627=z+237=21\frac{x-4}{\frac{6}{7}}=\frac{y+6}{\frac{2}{7}}=\frac{z+2}{\frac{3}{7}}=21 (21×67+4,27×21−6,37×21−2)\left(21 \times \frac{6}{7}+4, \frac{2}{7} \times 21-6, \frac{3}{7} \times 21-2\right) =(22,0,7)=(a,b,c)=(22,0,7)=(a, b, c) ∴324+144+16=22 \therefore \sqrt{324+144+16}=22

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
3D Geometry
Topic
Vector & Cartesian forms of lines and planes