Find the value of λ for which the given planes are perpendicular to each other:

(i) and


(ii) and


For planes perpendicular Cos90°=0

(1)


(i)On comparing with the standard equation of a plane




2.3 + (-1).2 + (-λ).2=0


6-2-2λ=0


2λ=4


λ=2


(ii) On comparing with the standard equation of a plane




λ.1 + 2.2 + 3.(-7)=0 λ + 4-21=0 λ=17


1