Let `veca= 2 hati + 3hatj - 6hatk, vecb = 2hati - 3hatj + 6hatk and vecc = -2 hati + 3hatj + 6hatk`. Let `veca_(1)` be the projection of `veca` on `vecb and veca_(2)` be the projection of `veca_(1)` on `vecc` . Then
`veca_(2)` is equal to (A) `943/49 (2 hati - 3hatj - 6hatk)` (B) `943/(49^(2)) (2 hati - 3hatj - 6hatk)` (C) `943/49 (-2 hati + 3hatj + 6hatk)` (D) `943/(49^(2)) (-2 hati + 3hatj + 6hatk)`

Options

A. `veca and vcea_(2)` are collinear
B. `veca_(1) and vecc` are collinear
C. `veca m veca_(1) and vecb` are coplanar
D. `veca, veca_(1) and a_(2)` are coplanar

Answer

c

Explanation

`veca,veca_(1)andvecb` are coplanar because `veca_(1) and vecb` are collinear.