What is the condition that two non-zero vectors are (a) orhtogonal and (b) collinera?

Answer

(a) `vecA. vecB=0` and (b) `vecA xx vecB =0`

Explanation

(a) `vecA. vecB =0`
`rArr |vecA||vecB| cos theta90 ^(@)`
(b) `vecA xx vecB =0`
`rArr |vecA||vecB| sin 0^(@) =0`