Question

If the mirror image of the point (1, 3, 5) with respect to the plane 4x - 5y + 2z = 8 is (α, β, γ), then 5(α + β + γ) equals :

(1) 47

(2) 43

(3) 39

(4) 41

Answer 1

Point Q is image of point P w.r.to plane, M is mid point of P and Q, lies in plane

Also PQ perpendicualr to the plane

5(α + β + γ) = 13 + 5 + 29 = 47