The direction ratio of normal to the plane through the points (0, −1, 0) and (0, 0, 1) and making an angle 
with the plane y−z+5=0 are
(a)
2
, 1, −1
(b)
2, 2, −
(c)
2, −1, 1
(d)
The direction ratio of normal to the plane through the points (0, −1, 0) and (0, 0, 1) and making an angle with the plane y−z+5=0 are
(a)
2, 1, −1
(b)
2, 2, −
(c)
2, −1, 1
(d)
Question ID - 56989 | SaraNextGen Top Answer
The direction ratio of normal to the plane through the points (0, −1, 0) and (0, 0, 1) and making an angle with the plane y−z+5=0 are
(a)
2, 1, −1
(b)
2, 2, −
(c)
2, −1, 1
(d)
|
The direction ratio of normal to the plane through the points (0, −1, 0) and (0, 0, 1) and making an angle |
|||
|
(a) |
2 |
(b) |
2, 2, − |
|
(c) |
2, −1, 1 |
(d) |
|
1 Answer
127 votes
Answer Key / Explanation : (d) -
Let the equation of plane be
a(x−0)+b(y+1)+c(z−0)=0
It passes through(0, 0, 1) then
b+c=0 …..(1)
now cos
=
⇒a2=−2bc and b=−c
We get a2=2c2
⇒a=
⇒direction ratio (a, b, c)=(
, −1, 1) or (
1, −1)
127 votes
Answer Link
127