Let a =2 i + j -2 k and b = i + j . If c is a vector such that a c =| c |,| c - a |=2 2 and the angle between a b and c is 2 3 , then |( a b ) c |=

Step-by-step solution

aligned & | c - a |=2 2 & | c |^2+| a |^2-2( a c )=8 & . | c |^2+9-2| c |=8 [ a c =| c | (given ) ] & (| c |-1)^2=0 & c =1 aligned Now, aligned |( a b ) c | & =| a b || c | 2 3 & =| a b |(1) ( 3 2 ) & = 3 3 2 & [ a b =2 i -2 j + k ] aligned