Three Dimensional Geometry Question 152
Question: If the planes $ x+2y+kz=0 $ and $ 2x+y-2z=0 $ are at right angles, then the value of k is
[MP PET 1999]
Options:
A) $ -\frac{1}{2} $
B) $ \frac{1}{2} $
C) ? 2
D) 2
Show Answer
Answer:
Correct Answer: D
Solution:
Obviously, $ ,2,(1)+1,(2)-2,(k)=0\Rightarrow k=2 $ .
BETA
