If C=∙A∙B, what must be true about the directions and magnitudes of AS and B if C=A+B? What must be true about the directions and magnitudes of  A and B if C=0?

Q1.17 If C = A + B, what must be true about the directions and magnitudes of A and B if C = A + B? What must be true about the directions and magnitudes of A and B if C = 0?

 If is the vector sum of and , = + , what must be true about the directions 
and magnitudes of and if =  + ? What must be true about the directions and 
magnitudes of and if = 0? 

If is the vector sum of and , = + , what must be true about the directions
and magnitudes of and if =  + ? What must be true about the directions and
magnitudes of and if = 0?