If a = 1 10 (3 i + k ) and b = 1 7 (2 i +3 j -6 k ) , then the value of (2 a - b ) [( a b ) ( a +2 b )] is

Step-by-step solution

Here, a b =0 a and b are perpendicular unit vectors. Now, (2 a - b ) ( a b ) ( a +2 b ) = [ array lll 2 a - b & a b & a +2 b array ] aligned & =-[ a b 2 a - b a +2 b ] & =-( a b ) (2 a - b ) ( a +2 b ) & =-( a b ) 5( a b ) & =-5| a b |=-5| a |^2| b |^2 & =-5 aligned aligned & [ a b ] & [ | a |=| b |=1] aligned