Three Dimensional Geometry Question 320
Question: The ratio in which the join of points (1, -2, 3) and (4, 2, -1) is divided by XOY plane is
Options:
A) 1:3
B) 3:1
C) -1:3
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Let A(1, -2, 3) and B (4, 2, -1). Let the plane XOY meet the line AB in the point C such that C divides AB in the ratio k : 1, then $ C\equiv ( \frac{4k+1}{k+1},\frac{2k-2}{k+1},\frac{-k+3}{k+1} ) $ . Since C lies on the the plane XOY i.e. the plane z=0, therefore, $ \frac{-k+3}{k+1}=0\Rightarrow k=3. $
BETA
