Anonymous

# Given u=[1 2 1], v=[-2 3 2] and w=[4 -1 3], find a scalar k such that ku+v is perpendicular to w?

having a bit of trouble understanding how i would make this perpendicular. help would be appreciated

### 2 Answers

Relevance

- Anonymous1 decade agoFavorite Answer
m = ku+v

m = k{1,2,1} + {-2,3,2}

m = {k-2, 2 k+3, k+2}

vector m perpendicular to w if

m • w = 0

{k-2, 2 k+3, k+2} • {4,-1,3} = 0

5 (k-1) = 0

k = 1

- 1 decade ago
look multiply k with u it becomes ki + 2kj + kk and else v is -2i + 3j + 2k .... adding both of them u get (k-2)i + (2k +3)j + (k+2)k is ku + v ... similarly w = 4i -j + 3k ... as they are perpendicular ... so their dot product will be zero .... (ku+v).w = 0 .... doing this u wud get k .. dothis yourself ... and enjoy this ... i won't make your way that easy ... best of luk .. :)

Source(s): Meee

Still have questions? Get your answers by asking now.