Let c be a vector perpendicular to the vectors a = i + j - k and b = i +2 j + k . If c .( i + j +3 k )=8 then...

Question

Let c be a vector perpendicular to the vectors a = i + j - k and b = i +2 j + k . If c .( i + j +3 k )=8 then the value of c .( a b ) is equal to ________.

Accepted Answer

28

JEE Main 2021 Mathematics question

Solution