JEE Main2016MathematicsVector AlgebraActual
The number of distinct real values of λ , for which the lines x - 1 1 = y - 2 2 = z + 3 λ 2 and x - 3 1 = y - 2 λ 2 = z - 1 2 , are coplanar is
Options
- A2
- B4
- C3
- D1
Correct answer
C. 3
Step-by-step solution
∵ Lines are coplanar ∴ 3 - 1 2 - 2 1 - - 3 1 2 λ 2 1 λ 2 2 = 0 ⇒ 2 0 4 1 2 λ 2 1 λ 2 2 = 0 ⇒ 2 4 - λ 4 + 4 λ 2 - 2 = 0 ⇒ 4 - λ 4 + 2 λ 2 - 4 = 0 ⇒ λ 2 λ 2 - 2 = 0 ⇒ λ = 0 ,   2 ,   - 2