Find 
when 
and 
We will first find vector product of 
and 
then scalar product of that with 
.
= 2.3 + 1.(5) + 3.(- 7)
= 6 + 5 - 21
= - 10
1
Find when and
We will first find vector product of and then scalar product of that with .
= 2.3 + 1.(5) + 3.(- 7)
= 6 + 5 - 21
= - 10