If the volume of parallelopiped formed by the vectors \stackrel{ \^}{ {i}}+\\lambda\stackrel{ \^}{ {j}}+ \stackrel{ \^}{ {k}}, \stackrel{ \^}{ {j}}+\\lambda \stackrel{ \^}{ {k}} and \\lambda\stackrel{ \^}{ {i}}+ \stackrel{ \^}{ {k}} is minimum, then \lambda is equal to: [12 Apr 2019 Shift 1]