If the position vectors off A,B,C and D are `2hati+hatj,hati-3hatj,3hati+2hatj and hati+lamdahatj`, respectively and `AB||CD`, then `lamda` will be

Options

A. `-7`
B. 7
C. `-6`
D. None of these

Answer

C

Explanation

Now, `PQ= (hati - 3 hatj)-(2 hati + hatj) = - hati-4hatj`
`and RS= - 2hati + (mu - 2)hatj`
Given, `PQ||RS rArr PQ= lambda RS`
`-hati - 4 hatj =[ lambda { - 2hati +(mu-2)hatj}]`
`rArr lambda = 1//2 and mu = -6 `