Mark the correct alternative in each of the following: Let be three unit vectors such that is perpendicular to . If makes angle α and β respectively, then cos α + cosβ =

Question

Philoid · Accepted Answer

We know that,

(i)

Since,

is perpendicular to

=0

And according to question

=1

We can rewrite equation (i) as

1=1+1+1+0+2(cos α + cosβ)

cos α + cosβ = -1 Ans.

Mark the correct alternative in each of the following:Let be three unit vectors such that is perpendicular to . If makes angle α and β respectively, then cos α + cosβ =

Mark the correct alternative in each of the following:
Let be three unit vectors such that is perpendicular to . If makes angle α and β respectively, then cos α + cosβ =