Question

The plane divides the join of $( 1 , - 1,5 )$ and (2, 3, 4) in the ratio $\lambda : 1$ , then $\lambda$ is

• A. – 3
• B. 3
• C. $- \frac { 1 } { 3 }$
• D. $\frac { 1 } { 3 }$

Answer 1

Answer: (D)

$\frac { 1 } { 3 }$

Answer 2

Since ZOX plane i.e. $y = 0$ divides the join of (1,–1, 5) and (2, 3, 4) in the ratio $\lambda : 1$. $\therefore \frac { 3 \lambda - 1 } { \lambda + 1 } = 0 \Rightarrow \lambda = \frac { 1 } { 3 }$ .