Question

Find a so that the vectors v = i + aj and w = 3i + 2j are orthogonal.

Answer 1

@jim_thompson5910

Answer 2

v and w are orthogonal if and only if the dot product of the two vectors is 0.


v dot w = 0

(i + aj) dot (3i + 2j) = 0

1*3 + a*2 = 0

3 + 2a = 0

a = ???

Answer 3

@abb0t

Answer 4

a = -3/2 ?

Answer 5

correct

Answer 6

so if it were W = -4i -2j than it would be -4 -2a = 0 ?

Answer 7

yes

Answer 8

alright so it'd be -2, thank you.