Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Three-dimensional Geometry

Question:

The value of \(x\) for which the lines \(\frac{x-1}{-3}=\frac{y-2}{2k}=\frac{z-3}{2}\) and \(\frac{x-1}{3k}=\frac{y-1}{1}=\frac{z-6}{-5}\) are perpendicular is

Options:

\(\frac{7}{10}\)

\(\frac{10}{7}\)

\(-\frac{10}{7}\)

\(0\)

Correct Answer:

\(-\frac{10}{7}\)

Explanation:

Lines are perpendicular there for \(a_{1}a_{2}+b_{1}b_{2}+c_{1}c_{2}=0\)

⇒ −3(3k)+2k×1+2(5)=

$ \Rightarrow 7k = -10$

$\Rightarrow k = \frac{-10}{7}$