Three Dimensional Geometry Question 170

Question: The line $ \frac{x+3}{3}=\frac{y-2}{-2}=\frac{z+1}{1} $ and the plane $ 4x+5y+3z-5=0 $ intersect at a point

Options:

A) (3, 1, ?2)

B) (3, ? 2, 1)

C) (2, ?1, 3)

D) (?1, ?2, ?3)

Show Answer

Answer:

Correct Answer: B

Solution:

Line is $ \frac{x+3}{3}=\frac{y-2}{-2}=\frac{z+1}{1}=\lambda , $ (Let) $ x=3\lambda -3;y=-2\lambda +2;z=\lambda -1 $ line intersects plane, therefore, $ 4(3\lambda -3)+5(-2\lambda +2)+3(\lambda -1)-5=0 $ $ \Rightarrow \lambda =2 $ . So, $ x=3;y=-2;z=1 $ . Trick : Since the point (3, ? 2, 1) satisfies both the equations.