Exams Joint Entrance Examination Mathematics 3D Geometry Question 514 Question 514 of 521 Medium MCQ
If the line \[\frac{2-x}{3}=\frac{3 y-2}{4 \lambda+1}=4-z\] makes a right angle with the line \[\frac{x+3}{3 \mu}=\frac{1-2 y}{6}=\frac{5-z}{7}\], then \[4 \lambda+9 \mu\] is equal to :
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\[ L 1 : x − 2 ( − 3 ) = y − 2 3 ( 4 λ + 1 3 ) = ( − 1 ) L 2 : x + 3 3 μ = y − 1 2 − 3 = z − 5 − 7 ∵ L 1 ⊥ L 2 ⇒ ( − 3 ) ( 3 μ ) + ( 4 λ + 1 3 ) ( − 3 ) + ( − 1 ) ( − 7 ) = 0 − 9 μ − 4 λ − 1 + 7 = 0 ⇒ 4 λ + 9 μ = 6 \begin{aligned}
& L_1: \frac{x-2}{(-3)}=\frac{y-\frac{2}{3}}{\left(\frac{4 \lambda+1}{3}\right)}=\frac{}{(-1)} \\
& L_2: \frac{x+3}{3 \mu}=\frac{y-\frac{1}{2}}{-3}=\frac{z-5}{-7} \\
& \because L_1 \perp L_2 \\
& \Rightarrow(-3)(3 \mu)+\left(\frac{4 \lambda+1}{3}\right)(-3)+(-1)(-7)=0 \\
& -9 \mu-4 \lambda-1+7=0 \\
& \Rightarrow 4 \lambda+9 \mu=6 \\
&
\end{aligned} L 1 : ( − 3 ) x − 2 = ( 3 4 λ + 1 ) y − 3 2 = ( − 1 ) L 2 : 3 μ x + 3 = − 3 y − 2 1 = − 7 z − 5 ∵ L 1 ⊥ L 2 ⇒ ( − 3 ) ( 3 μ ) + ( 3 4 λ + 1 ) ( − 3 ) + ( − 1 ) ( − 7 ) = 0 − 9 μ − 4 λ − 1 + 7 = 0 ⇒ 4 λ + 9 μ = 6 \] Answer the question to unlock