Question

From a point P(λ, λ, λ), perpendiculars PQ and PR are drawn respectively on the lines y = x, z = 1 and y = -x, z = -1. If P is such that ∠QPR is a right angle, then the possible value(s) of λ is(are) 

(A) √2 

(B) 1 

(C) -1 

(D) - √2

Answer 1

Correct option is (C) -1