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QJEEM25Ma1ae0: JEE Main 2025 Mathematics - Class 12 JEEM25Ma1ae0 Solution: The square of the distance of the point from the line in the…

The square of the distance of the point (157,327,7)\left( \frac{15}{7}, \frac{32}{7}, 7 \right) from the line x+13=y+35=z+57\frac{x + 1}{3} = \frac{y + 3}{5} = \frac{z + 5}{7} in the direction of the vector i^+4j^+7k^\hat{i} + 4\hat{j} + 7\hat{k} is:

Multiple Choice Options

  • A 66
  • B 54
  • C 41
  • D 44

Step-by-Step Verified Solution

JEE Main 2025 (Online) 28th January Evening Shift Mathematics - 3D Geometry Question 11 English Explanation

amp;L=x+13=y+35=z+57amp;PQ=x−1571=y−3274=z−77=λ\begin{aligned}& L=\frac{x+1}{3}=\frac{y+3}{5}=\frac{z+5}{7} \\& P Q=\frac{x-\frac{15}{7}}{1}=\frac{y-\frac{32}{7}}{4}=\frac{z-7}{7}=\lambda\end{aligned}

amp;⇒Q(λ+157,4λ+327,7λ+7)amp; Since Q lies on line Lamp;amp; So, λ+157+13=7λ+7+57amp;⇒7λ+22=21λ+36amp;⇒λ=−1amp;∴ Point Q(87,47,0)amp;PQ=(157−87)2+(327−47)2+(7−0)amp;PQ=66amp;⇒(PQ)2=66\begin{aligned}&\Rightarrow \mathrm{Q}\left(\lambda+\frac{15}{7}, 4 \lambda+\frac{32}{7}, 7 \lambda+7\right)\\&\text { Since } \mathrm{Q} \text { lies on line } \mathrm{L}\\&\begin{aligned}& \text { So, } \frac{\lambda+\frac{15}{7}+1}{3}=\frac{7 \lambda+7+5}{7} \\& \Rightarrow 7 \lambda+22=21 \lambda+36 \\& \Rightarrow \lambda=-1 \\& \therefore \text { Point } Q\left(\frac{8}{7}, \frac{4}{7}, 0\right) \\& \mathrm{PQ}=\sqrt{\left(\frac{15}{7}-\frac{8}{7}\right)^2+\left(\frac{32}{7}-\frac{4}{7}\right)^2+(7-0)} \\& \mathrm{PQ}=\sqrt{66} \\& \Rightarrow(\mathrm{PQ})^2=66\end{aligned}\end{aligned}

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