NTA Abhyas JEE Main2020MathematicsVector AlgebraPractice
A point α , β , γ satisfies the equation of the plane 3 x + 4 y + 7 z = 3 . The value of β , such that p → = α i ^ + β j ^ + γ k ^ satisfies the relation j ^ × j ^ × p → = 0 → , is equal to
Correct answer
0.75
Step-by-step solution
3 α + 4 β + 7 γ = 3 …. 1 j ^ × j ^ × p → = j ^ ⋅ p → j ^ - j ^ ⋅ j ^ p → = - α i ^ - γ k ^ = 0 ⇒ α = γ = 0 From equation 1 , we get, 4 β = 3 ⇒ β = 0.7 5