Skip to content
dronacharya.ai
← JEE Main 2022 · 28 Jul · Shift 2
MathematicsSingle correct+4 / -1Question 75 of 90

JEE Main 2022 · 28 Jul · Shift 2, Mathematics question 75

Let the lines x−1λ=y−21=z−32\dfrac{x-1}\lambda=\dfrac{y-2}1=\dfrac{z-3}2 and x+26−2=y+183=z+28λ\dfrac{x+26}{-2}=\dfrac{y+18}3=\dfrac{z+28}\lambda be coplanar and P be the plane containing these two lines. Then which of the following points does NOT lie on P?

Choose one option
Answer and worked solution

Official answer: D

Coplanar. The determinant of (−27,−20,−31)(-27,-20,-31), (λ,1,2)(\lambda,1,2), (−2,3,λ)(-2,3,\lambda) vanishes only at λ=3\lambda=3.

Plane. Normal (3,1,2)×(−2,3,3)=(−3,−13,11)(3,1,2)\times(-2,3,3)=(-3,-13,11) through (1, 2, 3): 3x+13y−11z=−43x+13y-11z=-4.

Check. (0, 4, 5) gives 52−55=−3≠−452-55=-3\ne-4, so it is not on P. (D)