JEE Main2014MathematicsThree Dimensional GeometryActual
If the angle between the line 2 x ⁡ + 1 = y ⁡ = z ⁡ + 4 and the plane 2 x ⁡ - y ⁡ + λ z ⁡ + 4 = 0 is π 6 , then the value of λ is
Options
- A4 5 7
- B1 3 5 1 1
- C1 3 5 7
- D4 5 1 1
Correct answer
A. 4 5 7
Step-by-step solution
Given line is L : x + 1 1 = y 2 = z + 4 2 and plane is P :   2 x - y + λ z + 4 = 0 . The angle between a line x - x 1 l = y - y 1 m = z - z 1 n and a plane a x + b y + c z + d = 0 is sin θ = a l + b m + c n a 2 + b 2 + c 2 l 2 + m 2 + n 2 sin π 6 = 2 × 1 + - 1 × 2 + 2 λ 1 2 + 2 2 + 2 2 2 2 + 1 2 + λ ⇒ 1 2 = 2 - 2 + 2 λ 1 + 4 + 4 4 + 1 + λ ⇒ 1 2 = 2 λ 3 5 + λ ⇒ 4 λ = 3 5 + λ Squaring both sides, we get ⇒ 1 6 λ = 9 5 +