If  are vectors such that  and  then possible value of  is

Concept:

• The cross product of vector to itself = 0
• The cross product of collinear vectors = 0
• The dot product of collinear vectors = Product of their Magnitudes
• For dot product 
• For cross product  
• The unit vector in the direction of a  
• A vector in direction of  = (Magnitude of ) ×

Calculation:

Given:

⇒ 

⇒ 

⇒ 

It means the  and  are collinear vectors.

∴  

⇒  

⇒ \(\boldsymbol{\rm\vec a + \vec b = 2\hat i + 3\hat j + 4\hat k}\)

⇒  

⇒  

⇒