Let `veca=hati+hatj+hatk, vecb=hati-hatj+2hatk and vecc=xhati+(x-2)hatj-hatk`. If the vector `vecc` lies in the plane of `veca and vecb` then x equals (A) 0 (B) 1 (C) -4 (D) -2
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Correct Answer – D
Since, given vectors a, b and c are coplanar.
`:. |{:(1,1,1),(1,-1,2),(x,x-2,-1):}| = 0`
`rArr 1{1-2(x-2)} -1(-1-2x)+ 1(x-2 +x) = 0`
`rArr 1 -2x + 4 + 1 + 2x + 2x- 2 = 0`
`rArr 2x = – 4`
`x = – 2`